Prepare the Dough:

In a large mixing bowl, beat the softened butter and cream cheese until smooth and creamy. Add the egg and vanilla extract, mixing until well combined.

Gradually mix in the yellow cake mix until a soft dough forms.

Chill the Dough:

Cover the bowl with plastic wrap and refrigerate the dough for at least 1 hour. This makes it easier to handle and prevents spreading during baking.

Preheat Oven:

Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper or silicone baking mats.

Shape and Coat:

Scoop about 1 tablespoon of chilled dough and roll it into a ball. Roll the dough ball in powdered sugar until fully coated. Place the balls on the prepared baking sheets, about 2 inches apart.

Bake:

Bake in the preheated oven for 10-12 minutes, or until the edges are set and the tops are slightly cracked. The centers will still look soft, which is normal.

Cool:

Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.