Easy Overnight High Protein French Toast Casserole

This protein french toast casserole is a delicious overnight breakfast that tastes like a classic french toast bake but with an extra protein boost to keep you full and energized AND can be done the night before for easy morning meal prep! Instead of a sugary morning that leads to a sugar crash, this version uses cottage cheese, whole eggs, and optional vanilla protein powder to add a serious protein boost. It’s perfect for weekends, special occasions, or even meal prep, since you can assemble it ahead and bake it the next morning.

I love creating high-protein breakfast recipes that still feel like a treat, and this one checks every box. It has a golden, crisp top, a custardy center, fluffy bread pieces, and warm cinnamon-sugar flavor. Everything you want in a french toast casserole recipe, made with healthy ingredients but without sacrificing comfort. It’s also a great way to reduce food waste, since stale bread works beautifully in a french toast bake.

Whether you serve it with fresh berries, a drizzle of maple syrup, or even a swipe of peanut butter for more protein, this casserole always feels like a crowd pleaser. It’s a great addition to your meal plan, brunch table, or holiday menu and always a hit with the whole family.

If you're looking for more easy high protein make ahead recipes, try this high protein overnight oats with cottage cheese, cinnamon roll baked protein oatmeal, everything bagel casserole, or this Christmas morning casserole (that's perfect all year round!) Or check out any of these 25+ Easy Gluten Free Breakfast Ideas for Busy Mornings ideas!

Why You'll Love This Overnight Breakfast Casserole Recipe

• It’s a healthy breakfast recipe that tastes like traditional french toast but delivers much protein per serving thanks to cottage cheese, whole eggs, and (optional) vanilla protein powder.
• You can assemble it the night before, cover with plastic wrap, and bake the next morning for effortless hosting or simple meal prep to beat those busy mornings.
• The combination of fluffy bread cubes, a custardy center, and crispy edges makes this a comforting yet macro-friendly twist on a classic french toast recipe.

Please note this post contains affiliate links.

Protein French Toast Ingredients & Tested Substitutions

• Brioche or challah bread. About 14 oz, cut into cubed bread or smaller pieces. Fresh bread or stale bread both work. You can use gluten-free brioche, whole wheat bread, white bread, or even low carb bread if you want fewer carbs.
• Milk of choice. Makes the custard creamy. Use almond milk, whole milk, or oat milk, any works for the french toast batter.
• Cottage cheese. Adds creaminess and extra protein without affecting the custardy texture. Greek yogurt can be substituted for a tangier twist.
• Whole eggs & egg whites. Whole eggs bring richness, while egg whites help increase total protein content without adding many calories.
• Coconut sugar or brown sugar. Sweetens the casserole without overwhelming it. If you prefer less added sugar, use a reduced amount. I love using coconut sugar for this recipe, which adds a wonderful caramel-like depth that pairs perfectly with the spices.
• Butter. Helps the casserole bake to a golden brown finish.
• Vanilla extract & cinnamon. Classic flavor pairings for a traditional french toast moment. Add a touch of almond extract or lemon zest for brightness.
• Kosher salt. Balances the sweetness.
• Vanilla protein powder. A great way to give your french toast bake even more protein. Protein powder adds sweetness and a major protein boost. I like to use this brand but you can use a scoop of your favorite protein powder if you prefer.
• Toppings. Drizzle of maple syrup, fresh berries, sliced bananas, or a spoonful of peanut butter for more healthy fats and flavor.

Protein French Toast Casserole Step by Step Instructions

1. Prep the baking dish. Preheat the oven to 350° Fahrenheit (skip if making overnight). Grease a 9x13 casserole dish with 1 tablespoon melted butter.

2. Mix the custard. In a large bowl, whisk together the whole eggs, egg whites, milk of choice, cottage cheese, melted butter, vanilla extract, cinnamon, brown sugar, and kosher salt until smooth. Tip: blend your cottage cheese up ahead of time if you do not like the texture of curds.

3. Prepare the brioche bread. Slice brioche into 1-inch bread pieces, then add them to the baking dish, packing tightly into an even layer.

4. Add the egg mixture. Pour the custard evenly over the bread so every cube gets a good bread soak.

5. Bake. Bake the casserole for 35 to 45 minutes or until the top is golden brown, the edges are crispy, and the center is custardy.

6. Serve. Top with fresh berries, maple syrup, or peanut butter. Serve warm.

Protein French Toast Casserole Expert Tips & Tricks

• For the best results, let the bread soak for at least 15 minutes before baking, or refrigerate overnight. If you have the time, overnight is absolutely best.
• Want more protein? Add 1 to 2 scoops of vanilla or cinnamon roll protein powder to the custard.
• Use stale or day-old slices of bread to help the casserole hold together better.
• Swap brioche for challah bread, gluten-free bread, or high-protein bread.
• If making ahead, cover tightly with plastic wrap and store in the fridge.

Protein French Toast Casserole FAQs

What type of milk should I use?

Honestly, whatever milk you already have will work fine. Whole milk gives you the richest custard, and almond or oat milk both work if you want it to have less dairy. But the hope is that this recipe is so easy that you already have most of these ingredients in your fridge and pantry.

Can I make this gluten free?

Absolutely. I actually more often than not, swap the brioche for a gluten free brioche (I like Franz a lot!) or any sturdy gluten free loaf you like. Follow the directions like normal with the gluten free bread. Every other ingredient in this recipe is already naturally gluten free.

What bread works best?

Brioche is my favorite because it's rich and soaks up the custard without falling apart. Challah works beautifully too. A high protein sandwich bread is a great option if you want more protein per serving, and a gluten free brioche bread is great for a gluten free dietary need. Day old bread is even better than fresh. Honestly, just like the milk, any bread can work for this recipe!

How do I know when the casserole is done?

You're looking for golden brown crispy edges and a center that's set but still custardy, usually around 35 to 45 minutes. If the top is browning faster than the middle is setting, tent it loosely with tin foil and keep baking like normal. You know that it is set when it jiggles slightly when you shake the pan.

Why is the middle still soggy?

Usually this means the protein french toast casserole just needs more time in the oven, especially if it went in cold from the fridge without sitting at room temperature (which is totally fine to do!). It could also be your oven temperature; some ovens run hotter or colder than it was set. Check with an oven thermometer if this is a constant problem when you bake.. You can also let it rest for 10 minutes after baking too, since it firms up as it cools in the pan.

Do I have to use protein powder?

Nope, protein powder is completely optional. The eggs, egg whites, cottage cheese, and milk are already doing a lot of the work of adding natural protein. Adding a scoop or two of vanilla protein powder will just help by adding a bit more protein in every bite for those who are looking for macro positive breakfasts.

How to Store & Reheat Protein French Toast Casserole

• Refrigerate: Store cooled leftovers in an airtight container for 3 to 4 days.
• Freeze: Wrap slices individually to freeze for up to 2 months.
• Reheat: Microwave or bake at 300°F (if you want those crisp edges again) until warmed through.

If you liked this overnight casserole recipe, you might also enjoy

• Easy High Protein Cottage Cheese Egg Bake Casserole
• Easy Overnight Everything Bagel Breakfast Casserole
• Chunky Monkey Waffle Casserole
• Brioche French Toast Casserole (Gluten Free)
• Make Ahead Christmas Morning Breakfast Casserole
• or any of these 25+ Easy Gluten Free Breakfast Ideas for Busy Mornings

Did you have a chance to make this recipe? If so, please leave me a 5 star rating and review below. I always love and appreciate hearing from you!