Preheat oven: Preheat the oven to 375° F and spray an 8×8 inch square baking dish with cooking spray.
Mix ingredients: In a large bowl, mix together the oats, banana, protein powder, almond milk, cashew butter, maple syrup, baking powder, cinnamon, salt, almond, vanilla, butter extract (if using) and 2 Tablespoons sprinkles.
Add to baking dish: Carefully pour oatmeal mixture into the prepared baking dish.
Bake: Bake for 35 to 40 minutes, until the top is nicely golden. Remove from the oven and let cool for a 10-15 minutes.
Make frosting: While oatmeal is baking, make the frosting if you're planning to use it. Mix together softened cream cheese and yogurt and maple syrup.
Portion and serve. Top the baked oatmeal with frosting and remaining sprinkles. Drizzle each portion with additional cashew butter for serving.
For storage: store baked oatmeal and frosting in separate airtight containers in the refrigerator for up to 4 days.
To reheat: To reheat the whole baked oatmeal (without frosting), cover with foil and reheat in a 350°F oven for about 20 minutes. For individual portions, set oven (or toaster oven) to 350°F and bake for 5-10 minutes or reheat in the microwave for 1 minute. Once warm add icing (if using) and serve.