In a large mixing bowl, cream together the softened unsalted butter and cream cheese until smooth and creamy, about 2-3 minutes.

Mix in one large egg and one teaspoon of pure vanilla extract until well combined and slightly fluffy, about 1-2 minutes.

Gradually add the yellow cake mix to the wet ingredients, mixing on low speed until fully incorporated.

Cover the bowl tightly with plastic wrap and refrigerate the dough for at least 30 minutes.

Preheat your oven to 350°F (175°C). Scoop tablespoon-sized portions of the chilled dough and roll them into balls, coat in powdered sugar.

Place sugary dough balls onto a parchment-lined baking sheet, leaving space between each. Bake for 10-12 minutes.

Allow the cookies to cool on the sheet for about 5 minutes before transferring them to a wire rack.