Using a large bowl, cream together the butter and cream cheese until combined and smooth
Beat in the egg and vanilla until combined
Add cake mix and stir until smooth
Fold in ¾ C of the sprinkles
Cover with plastic wrap and place into the fridge overnight
To Bake The Cookies: Put the powdered sugar in a shallow bowl
Preheat the oven to 350 degrees and line two cookie sheets with parchment paper or a silicone mat
Using a small cookie scoop, scoop out some of the dough and roll into a ball
Roll the ball in the powdered sugar until completely coated
Place onto the cookie sheets
Bake in the oven for 8-10 minutes or until lightly brown
Allow to cool for a few minutes before placing onto a wire rack to cool completely
To Dip The Cookies: Line a baking sheet with parchment and set aside
Using a heat safe bowl, melt the white chocolate in 30 second increments in the microwave until completely melted
Carefully Dip half of the cookie into the white chocolate
Very gently shake any excess white chocolate off
Place the cookie onto the parchment paper or silicone mat
Sprinkle with the leftvoer Christmas sprinkles
Allow the chocolate to completely harden