Grease a 9×13-inch baking dish with butter or cooking spray.

Spread half of the cubed bread evenly across the bottom of the dish.

Scatter dollops of softened cream cheese over the bread layer, followed by half of the blueberries.

Layer the remaining bread cubes on top, followed by the rest of the blueberries.

In a large mixing bowl, whisk together eggs, milk, heavy cream, granulated sugar, vanilla extract, and cinnamon (if using). Pour the mixture evenly over the bread, ensuring all pieces are soaked. Press down gently with a spatula to help the bread absorb the liquid.

Cover the dish with plastic wrap or foil and refrigerate for at least 2 hours or overnight for best results.

Preheat the oven to 350°F (175°C). Remove the casserole from the refrigerator and let it sit at room temperature while the oven preheats.

Bake for 45–50 minutes, or until the top is golden brown, the custard is set, and the center is no longer jiggly.

Let the casserole cool for 5–10 minutes before slicing. Dust with powdered sugar and serve warm. Optional: drizzle with maple syrup for extra sweetness.