In a large bowl, whisk together eggs, milk, heavy cream, sugar, vanilla extract, and cinnamon.
Add the bread cubes to the mixture and toss to coat. Let it sit for 30 minutes to allow the bread to soak up the liquid.
Preheat the oven to 350°F (175°C). Grease a baking dish and add half of the bread mixture.
Sprinkle half of the mixed berries over the bread.
Add the remaining bread mixture on top and scatter the rest of the mixed berries.
Drizzle maple syrup over the casserole.
Bake for 45-50 minutes or until the top is golden and the center is set.
Dust with powdered sugar before serving.