Cupcakes: Use #12 scoop to portion 3 oz. (about 1/3 cup) batter into each of 48 greased muffin cups. Bake in 300°F convection oven 10 min. or until toothpick inserted in centers comes out clean. Cool in pans 10 min.; transfer to parchment-lined sheet pans.
OREO Creme Frosting: Beat cream cheese and OREO Creme Icing Variegate in large bowl with mixer fitted with paddle attachment until well blended. Fold in OREO Pieces.
Assembly: Fit pastry bag with plain round tip; insert tip into top of each cupcake, then pipe about 1 Tbsp. OREO Creme Frosting into cupcake.
Spread 1/3 cup of the remaining frosting onto top of each cupcake; smooth top. Pour about 1/4 cup warm ganache over each cupcake, completely covering top and letting excess drip down side. Cool. Drizzle each cupcake with about 1/2 tsp. Variegate.