Prepare the bread base:

Coat a 9x13-inch baking dish with nonstick spray. Layer the cubed sourdough bread in an even layer across the bottom of the dish. Set aside.

Whisk the custard:

In a medium bowl, whisk together the eggs, milk, Greek yogurt, maple syrup, vanilla extract, and ground cinnamon. Mix well until fully combined.

Combine and refrigerate:

Pour the egg mixture evenly over the bread, making sure to coat every piece. Cover the dish tightly with plastic wrap or aluminum foil and refrigerate for at least 4 hours (overnight is best to let the bread soak fully).

Bake the casserole:

Preheat your oven to 350°F. Remove the casserole from the fridge while the oven is preheating.

Cover the casserole with foil and bake for 25 minutes. After 25 minutes, remove the foil and bake for an additional 20–25 minutes until the casserole is set and golden on top.

Prepare the cream cheese drizzle:

While the casserole bakes, make the drizzle. In a small bowl, combine the cream cheese, maple syrup, and milk. Use a hand mixer or whisk to blend until smooth and pourable. Adjust the milk to get the desired consistency for drizzling.

Assemble and serve:

Once the casserole is baked and golden, remove it from the oven. Top it with fresh mixed berries and drizzle the cream cheese mixture on top. Serve immediately and enjoy!