In a stand mixer fitted with the paddle attachment, mix together 100% cake mix, 37.5% water, and 6.25% oil on low until it comes together. Mix on medium speed for 2 minutes. Stir in 25% sprinkles by hand. Using a #40 purple scoop, deposit .5 oz. scoops onto sheet trays lined with parchment paper. Bake at 375°F for 10-12 minutes. Once cooled, using a straight tip, pipe a swirl of buttercream in the center of half the cake circles, top each with another half.
White Cake, Whoopie, Pie, Buttercreme, Buttercream, Pink, Blue, Yellow, Pastel, Confetti, Sprinkles