High-Protein French Toast Breakfast Casserole with Berries Make Ahead

Name: High-Protein French Toast Breakfast Casserole with Berries Make Ahead
Prep time: 15 min
Cook time: 45 min
Total time: 9 h
Yield: 8 servings
Cuisine: American
Ingredients: 600 g whole grain sourdough bread (cut into roughly 2cm cubes, slightly stale works best); 6 large eggs; 250 g plain non-fat Greek yogurt (adds creaminess and protein without heavy cream); 300 ml unsweetened almond milk (or any low-fat milk of your choice); 2 tbsp pure maple syrup (plus extra for serving if desired); 2 tsp vanilla extract; 1.5 tsp ground cinnamon; 0.25 tsp ground nutmeg; 0.25 tsp fine sea salt; 150 g fresh or frozen blueberries (if using frozen, do not thaw first); 150 g fresh or frozen raspberries (if using frozen, do not thaw first); 1 tbsp chia seeds (optional, stirred into the custard for extra fibre); 1 tsp lemon zest (brightens the berry flavour); 1 tbsp coconut oil (for greasing the baking dish); 2 tbsp rolled oats (scattered on top for a light crunch); 1 tsp coconut sugar (sprinkled on top before baking for a gentle caramelised crust)

High ProteinMeal Prep

Prep Time15 min

Cook Time45 min

Servings8

Calories285 kcal

Health Score7/10

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High-Protein French Toast Breakfast Casserole with Berries Make Ahead

There is something genuinely magical about waking up knowing breakfast is already done. This French toast breakfast casserole with berries make ahead recipe was designed for exactly that feeling. You do the work the night before, everything soaks beautifully overnight, and by morning all you need to do is slide a dish into the oven and wait for your kitchen to smell absolutely incredible. No standing over a hot pan flipping individual slices. No rushing. Just a warm, golden, berry-loaded casserole waiting for you.

What makes this version genuinely different from the traditional recipes you might have seen is the nutrition profile. Most French toast casseroles lean hard on heavy cream, loads of white sugar and white bread with very little going for them beyond tasting great. This recipe uses whole grain sourdough for extra fibre and a lower glycemic response, swaps heavy cream for a combination of unsweetened almond milk and plain Greek yogurt, and cuts the added sugar right down. The egg to bread ratio is generous, which pushes the protein content up significantly. Each serving delivers around 22 grams of protein, which is a serious upgrade from most breakfast casserole recipes. The berries, a mix of blueberries and raspberries, add natural sweetness, antioxidants and more fibre without needing much extra sugar at all.

The custard base here is really the heart of the recipe. Greek yogurt whisked into the egg and milk mixture does two things at once. It makes the custard slightly thicker and creamier without adding fat, and it boosts the protein content in a way you genuinely cannot taste. A little vanilla extract, a pinch of cinnamon and just a small drizzle of pure maple syrup round everything out. The bread cubes soak up all of this overnight and become this wonderfully soft, almost pudding-like texture in the centre, while the top layer catches the heat and turns golden and slightly crisp. The berries bubble up around the edges as it bakes and create little pockets of jammy fruit throughout the whole dish. It is exactly as good as it sounds.

Assembling this make ahead breakfast casserole takes about fifteen minutes in the evening, and then you just cover the dish and refrigerate it until morning. When you are ready to bake, pull it out while the oven preheats to take the chill off slightly, then bake until puffed and golden. It serves eight people comfortably, making it brilliant for family breakfasts, weekend guests or simply a week of meal-prepped morning slices you can reheat quickly before work. Serve it with a little extra fresh fruit on top, a dollop of Greek yogurt on the side or a drizzle of honey if you want something a touch sweeter. However you serve it, this casserole is the kind of make ahead breakfast that makes your whole morning feel more manageable.

Ingredients

Serves:8

600 g whole grain sourdough bread (cut into roughly 2cm cubes, slightly stale works best)
6 large eggs
250 g plain non-fat Greek yogurt (adds creaminess and protein without heavy cream)
300 ml unsweetened almond milk (or any low-fat milk of your choice)
2 tbsp pure maple syrup (plus extra for serving if desired)
2 tsp vanilla extract
1.5 tsp ground cinnamon
0.3 tsp ground nutmeg
0.3 tsp fine sea salt
150 g fresh or frozen blueberries (if using frozen, do not thaw first)
150 g fresh or frozen raspberries (if using frozen, do not thaw first)
1 tbsp chia seeds (optional, stirred into the custard for extra fibre)
1 tsp lemon zest (brightens the berry flavour)
1 tbsp coconut oil (for greasing the baking dish)
2 tbsp rolled oats (scattered on top for a light crunch)
1 tsp coconut sugar (sprinkled on top before baking for a gentle caramelised crust)

Instructions

1
Lightly grease a 9x13 inch baking dish with coconut oil. Arrange the bread cubes in an even layer across the bottom of the dish. They can overlap and pile slightly, that is perfectly fine.
Using bread that is a day or two old makes a real difference. Fresh bread can become too soggy. If your bread is fresh, spread the cubes on a baking tray and leave them out for a few hours to dry slightly before using.
2
In a large mixing bowl, whisk together the eggs, Greek yogurt, almond milk, maple syrup, vanilla extract, cinnamon, nutmeg and sea salt until completely smooth and well combined. Stir in the chia seeds and lemon zest if using.
Whisk the Greek yogurt in first before adding the milk so it dissolves smoothly without any lumps remaining.
3
Pour the custard mixture evenly over the bread cubes in the baking dish. Use a spatula or the back of a spoon to gently press the bread down so every piece begins to absorb the liquid.
4
Scatter the blueberries and raspberries evenly over the top of the soaked bread. Gently press a few berries down between the bread cubes so they are distributed throughout the casserole, not just sitting on the surface.
If using frozen berries, scatter them straight from the freezer. They will release their juices slowly overnight and throughout baking, which adds lovely colour to the dish.
5
Sprinkle the rolled oats and coconut sugar evenly over the top of the casserole. Cover the dish tightly with plastic wrap or a fitted lid and refrigerate for at least 8 hours or overnight.
You can refrigerate this for up to 18 hours before baking. The longer soak gives a softer, more pudding-like texture in the centre.
6
When you are ready to bake, remove the casserole from the fridge and allow it to sit at room temperature while your oven preheats to 180 degrees Celsius (350 degrees Fahrenheit). This takes about 10 to 15 minutes.
Do not skip the resting step. Putting a cold dish straight into a hot oven can affect baking time and result in uneven cooking.
7
Remove the cover and bake the casserole uncovered for 40 to 45 minutes, until the top is golden, the edges are set and the centre is no longer liquid when you gently shake the dish. A knife inserted into the centre should come out mostly clean.
If the top is browning too quickly before the centre is set, loosely lay a piece of foil over the dish for the final 10 minutes of baking.
8
Remove from the oven and allow the casserole to cool for 5 minutes before slicing and serving. This resting time helps the slices hold together neatly. Serve with a spoonful of Greek yogurt and fresh berries on top if you like.

Nutrition per serving

285kcal

Calories

22g

Protein

34g

Carbs

Fat

Fibre

10g

Sugar

310mg

Sodium

Pro Tips

✓
Whole grain sourdough is the ideal bread choice here because it has a sturdy crumb that holds up to the overnight soak without turning to mush, and it adds extra fibre and a gentle tang that pairs beautifully with the berries.
✓
The casserole will puff up significantly while baking and then settle slightly as it cools. This is completely normal and does not affect the taste or texture.
✓
For a higher protein boost, swap the almond milk for low-fat dairy milk or add an extra egg to the custard mixture.
✓
Mix up your berries based on what is in season. Blackberries, sliced strawberries and even diced peaches all work wonderfully in this recipe.
✓
Cutting the casserole into portions and storing them individually makes weekday reheating extremely quick and easy.
✓
If you prefer a slightly sweeter result, increase the maple syrup to 3 tablespoons or add a small drizzle over each serving at the table.

Frequently Asked Questions

Can I make this French toast breakfast casserole with berries the night before?↓

Yes, and that is actually the best way to make it. Assembling the casserole the night before and letting it soak overnight means the bread fully absorbs the custard, resulting in a much better texture than if you bake it immediately. Just cover it tightly and refrigerate for 8 to 18 hours before baking.

What bread works best for a make ahead French toast casserole?↓

Whole grain sourdough is the top choice for both texture and nutrition. It is sturdy enough to soak overnight without falling apart, and it adds extra fibre compared to white bread. A whole grain baguette or whole wheat sandwich bread also work well. Avoid very soft fresh bread as it can become too mushy after an overnight soak.

Can I use frozen berries instead of fresh?↓

Frozen berries work brilliantly in this recipe. Scatter them over the casserole straight from frozen without thawing. They will release their juices during the soak and baking, creating beautiful colour and flavour throughout the dish. Just be aware the casserole may need an extra 5 minutes in the oven if there is more liquid from frozen fruit.

How many calories are in this healthy French toast casserole?↓

Each serving contains approximately 285 calories, with around 22 grams of protein. This is significantly lower in calories and higher in protein than a traditional French toast casserole, which often comes in at 400 to 500 calories per serving with much less protein.

Can I make this casserole dairy free?↓

The recipe already uses almond milk, so the main swap needed is for the Greek yogurt. Use a thick, plain coconut yogurt or a dairy-free soy yogurt in the same quantity. The texture and protein content may vary slightly depending on the brand you choose.

How long does this casserole keep in the fridge after baking?↓

Once baked, the casserole keeps well in the fridge for up to 4 days when stored in an airtight container. Individual slices reheat quickly in the microwave in about 60 to 90 seconds, making this a great option for meal prepping a week of breakfasts.

Variations

•
Strawberry and Banana Version
Replace the blueberries and raspberries with sliced strawberries and thin banana slices. The banana adds natural sweetness so you can reduce the maple syrup to just 1 tablespoon. This version is especially popular with children.
•
Lemon Blueberry
Use all blueberries and increase the lemon zest to a full tablespoon. Add half a teaspoon of lemon extract to the custard for a bright, citrusy casserole that is refreshing and fragrant.
•
Chocolate Berry
Scatter 40 grams of dark chocolate chips over the berries before refrigerating. The chocolate melts during baking and creates rich pockets of flavour alongside the tart raspberries. Use 70 percent cocoa or higher for the best nutritional benefit.
•
Tropical Mango Raspberry
Swap the blueberries for diced fresh mango and keep the raspberries. Add a quarter teaspoon of ground ginger to the custard. The result is vibrant, slightly exotic and absolutely delicious in the warmer months.

Substitutions

•
Whole grain sourdough bread → Whole wheat baguette or whole grain sandwich bread (The bread should be slightly stale or dried out before using. Any sturdy whole grain bread with a firm crumb will work well.)
•
Plain non-fat Greek yogurt → Plain coconut yogurt or thick dairy-free soy yogurt (Use the same quantity. Choose a thick, unsweetened variety for the best result. The protein content will be lower with coconut yogurt.)
•
Unsweetened almond milk → Low-fat dairy milk, oat milk or soy milk (Any milk works here. Low-fat dairy milk will increase the protein content slightly. Oat milk adds a mild sweetness.)
•
Pure maple syrup → Raw honey or coconut nectar (Use the same quantity. Both alternatives are similar in sweetness and sugar content to maple syrup.)
•
Blueberries and raspberries → Strawberries, blackberries, cherries or diced peaches (Use any combination of fruit totalling around 300 grams. Fresh or frozen both work well in this recipe.)
•
Chia seeds → Ground flaxseed (Use the same quantity. Both add fibre and omega-3 fatty acids without affecting the flavour of the finished casserole.)

🧊 Storage

Allow the baked casserole to cool completely before storing. Cover the baking dish tightly with plastic wrap or transfer individual portions to airtight containers. Refrigerate for up to 4 days. To reheat, microwave individual slices for 60 to 90 seconds or warm in an oven preheated to 160 degrees Celsius for about 10 minutes. The casserole can also be frozen in individual portions for up to 2 months. Thaw overnight in the fridge before reheating.

📅 Make Ahead

This recipe is designed specifically as a make ahead breakfast. Assemble the casserole completely, including the berry topping and oat sprinkle, then cover tightly and refrigerate for a minimum of 8 hours and up to 18 hours before baking. Remove from the fridge while the oven preheats, then bake uncovered as directed. No adjustments to the baking time or temperature are needed after an overnight soak.