This Overnight Blueberry French Toast Casserole is everything you want in a cozy breakfast — soft custard-soaked bread, bursts of juicy blueberries, warm cinnamon, and a crunchy golden streusel topping. Prep it the night before, pop it in the oven in the morning, and enjoy an effortless brunch that tastes like a mix of blueberry pie and classic French toast.

It’s ideal for holidays, gatherings, or busy mornings when you want something special without doing any morning prep.

Why You’ll Love This Recipe

• Perfect make-ahead breakfast or brunch
• Sweet, comforting, bakery-style flavors
• Juicy blueberries in every bite
• Great for feeding a crowd
• 9×13 pan — perfect for potlucks and holidays
• Freezer-friendly
• Easy for beginners

Recipe Overview

Prep Time: 15 minutes
Chill Time: Overnight
Cook Time: 45–50 minutes
Total Time: 9–12 hours
Servings: 10–12

Ingredients

Casserole Base
• 1 loaf brioche or challah, cubed
• 1 ½ cups fresh or frozen blueberries
• 8 large eggs
• 2 cups whole milk
• 1 cup heavy cream
• ½ cup granulated sugar
• ¼ cup brown sugar
• 2 tsp vanilla extract
• 1 tsp cinnamon
• ¼ tsp salt

Streusel Topping
• ½ cup all-purpose flour
• ½ cup brown sugar
• 1 tsp cinnamon
• ¼ cup cold butter, cubed
• Pinch of salt

For Serving
• Powdered sugar
• Maple syrup
• Extra blueberries

Instructions

1. Prepare the Bread
   Grease a 9×13 baking dish. Add bread cubes and sprinkle blueberries evenly over the top.
2. Make the Custard
   In a large bowl, whisk eggs, milk, cream, sugars, vanilla, cinnamon, and salt. Pour evenly over the bread.
3. Chill Overnight
   Cover tightly and refrigerate for at least 8 hours so the bread absorbs all the custard.
4. Make the Streusel
   In a small bowl, mix flour, brown sugar, cinnamon, and salt. Cut in cold butter until crumbly.
   Refrigerate until morning.
5. Bake
   Preheat oven to 350°F (175°C). Sprinkle the streusel over the casserole.
   Bake 45–50 minutes until golden and set.
6. Serve Warm
   Dust with powdered sugar. Add maple syrup or fresh blueberries before serving.

Tips & FAQs

Can I use frozen blueberries?
Yes — use straight from the freezer; no thawing needed.

Can I freeze the casserole?
Freeze after assembling (before baking). Thaw overnight in the fridge and bake as directed.

What kind of bread works best?
Brioche, challah, or French bread. Stale bread works even better.

Can I bake it without chilling overnight?
Yes, but overnight soaking gives the best custardy texture.

Nutrition Summary

Serving Size	Calories	Protein	Carbs	Fat	Sugar	Fiber
1 serving	360	10g	42g	17g	22g	2g

(Estimated values.)