Microwave the Funfetti cake mix for 30 seconds to ensure any potential bacteria are killed, then allow it to cool completely before using.

In a mixing bowl, beat the softened unsalted butter together with light brown sugar until the mixture becomes light and fluffy, creating a creamy base.

Add the vanilla casein protein powder, whipped vanilla whey protein powder, cooled cake mix, almond extract, and almond milk to the creamed butter and sugar. Mix gently until just combined to maintain a soft, dough-like consistency.

Fold in the rainbow sprinkles carefully to distribute the colorful candy pieces evenly throughout the dough without breaking them.

Enjoy the protein cookie dough immediately as a delicious treat or transfer it to an airtight container and store it in the refrigerator for up to one week to maintain freshness and flavor.