In a big mixing bowl, combine eggs, heavy cream, milk, 2 tablespoons granulated sugar, cinnamon, and vanilla extract. Beat until everything is mixed together.
In another bowl, mix the cream cheese with the remaining sugar until it's smooth. Then, gently fold in the berries.
Slice the croissants down the middle to create a "pocket." Add 2-3 tablespoons of the cream cheese and berry mixture into each croissant. Arrange them in a greased 13x9 baking dish.
Pour the egg and cream mixture over the croissants. Cover the dish and let it chill in the refrigerator overnight.
When you're ready to bake, preheat the oven to 350°F. Bake the dish uncovered for 35-40 minutes or until it turns a beautiful golden brown.
Once it's out of the oven, give it a final touch by dusting powdered sugar over the top. Now, your Berry Stuffed Croissant French Toast Bake is ready to be enjoyed!