Preheat the oven to 350°F and line a baking sheet with parchment paper.
Blend the cottage cheese, egg, sugar, melted butter, vanilla extract, and almond extract until smooth.
Whisk the vanilla protein powder, all-purpose flour, oat flour, baking powder, and salt in a large bowl.
Stir the cottage cheese mixture into the dry ingredients until a soft dough forms.
Fold in the white chocolate chips and sprinkles, then chill the dough for 25 minutes.
Scoop 12 portions onto the baking sheet and flatten each one gently.
Bake for 11 to 13 minutes, until the edges are lightly golden. Cool the birthday cake cookies for 10 minutes before serving.