Preheat Oven: Set your oven to 350°F (175°C) and line a baking sheet with parchment paper.
Mix Wet Ingredients: In a large mixing bowl, beat the softened cream cheese and butter until smooth and creamy. Add the egg and mix until fully combined.
Add Cake Mix: Gradually mix in the yellow cake mix until a thick dough forms.
Fold in Sprinkles: Gently stir in the red sugar sprinkles, distributing them evenly throughout the dough.
Chill (Optional, but recommended): Cover the dough and refrigerate for about 30 minutes to make it easier to handle.
Scoop & Bake: Using a cookie scoop or spoon, drop dough balls (about 1 to 1.5 inches wide) onto the prepared baking sheet, spacing them about 2 inches apart.
Bake: Bake for 10-12 minutes, or until the edges are set and slightly golden. The centers may look soft but will firm up as they cool.
Cool & Enjoy: Let cookies rest on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.