01 -
Using a hand-held mixer or stand mixer fitted with the paddle attachment, beat the cream cheese and unsalted butter together on medium-high speed until smooth and creamy.
02 -
Add in the egg and vanilla extract, and continue to mix on medium-high speed. Scrape down the sides of the bowl as needed.
03 -
Reduce mixer speed to low and gradually add in the white cake mix until just combined.
04 -
Using a spatula or large spoon, fold in the rainbow colored sprinkles until evenly distributed.
05 -
Tightly cover the mixing bowl with plastic wrap and refrigerate for a minimum of 1 hour.
06 -
Adjust oven rack to the 2nd level mark (just above center) and preheat the oven to 350°F (175°C). Line 2 baking sheets with parchment paper or silicone mats.
07 -
Using a medium-size cookie scoop or spoon, portion the cookie dough into 1-inch balls. Roll each ball in powdered sugar, then place about 1½-2 inches apart on the prepared baking sheets. If desired, sprinkle a little sparkling sugar on top of each cookie.
08 -
Bake for 8-10 minutes at 350°F or until the bottoms turn a light golden brown.
09 -
Allow cookies to cool on the baking sheet for approximately 5 minutes before transferring to a wire cooling rack to cool completely. Use a spatula for transfer as the cookies will be very soft.
10 -
Store cookies in an airtight container at room temperature for up to 3 days or in the refrigerator for up to 5 days.