Preheat the oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper and lightly spray the sides with cooking spray.
Add the softened cream cheese, cottage cheese, eggs, casein protein powder, sugar alternative, cake batter flavoring, and salt to a food processor.
Blend until completely smooth, stopping to scrape the sides and bottom as needed. There should be no visible cottage cheese curds or dry pockets of protein powder.
Remove the food processor blade and gently fold in approximately 1/3 cup rainbow sprinkles with a spatula.
Pour the batter into the prepared springform pan and smooth the top.
Bake at 325°F for 60–65 minutes, until the edges are set but the center remains wobbly when the pan is gently moved.
Turn the oven off, crack the oven door slightly, and leave the cheesecake inside for 20 minutes.
Remove the cheesecake from the oven and let it cool completely at room temperature.
Once completely cool, refrigerate until chilled and firm before releasing the springform pan and slicing.
