1. Grease a 9×13 inch casserole dish.
2. Add the bread chunks to a large bowl and set aside.
3. In another large bowl, whisk together the eggs, milk, cream, cake mix, cinnamon and vanilla extract.
4. Pour the egg mixture over the bread chunks, then gently stir to combine.
5. Pour the bread mixture into the prepared casserole dish and spread evenly. Spread the sprinkles evenly over the top of the casserole. Cover the casserole and store in the fridge overnight.
6. When ready to bake the casserole, preheat the oven to 350°F (176°C).
7. Bake the casserole for about 25-30 minutes. While the casserole bakes, cut the additional cake mix into butter for the topping until it’s crumbly.
8. Remove the casserole from the oven and crumble the streusel over the top of the casserole.
9. Continue baking the casserole for another 10-25 minutes, or until it’s at your desired level of doneness.
10. Serve the casserole warm with frosting or syrup. To use the frosting, heat it in the microwave until pourable.