Place the 2 tablespoons of dry cake mix in a small microwave-safe bowl. Microwave on high for 30 to 45 seconds until the temperature reaches 160°F (71°C) to ensure the raw flour is heat-treated for safety. Set aside to cool.
In a medium mixing bowl, add the Greek yogurt and vanilla extract.
Sift the protein powder into the yogurt to prevent clumping.
Whisk the mixture vigorously with a spoon or small whisk until the protein powder is completely incorporated and the texture is glossy and smooth.
Fold in the heat-treated cake mix and the rainbow sprinkles until evenly distributed.
Taste and add optional sweetener if a higher level of sweetness is desired.
Serve immediately with high-protein graham crackers, apple slices, or animal crackers.