Preparation

• Heat oven to 350°F.
• Cut 12 cookies crosswise in half; reserve for later use. Chop remaining cookies.
• Prepare cake batter as directed on package; stir in chopped cookies. Spoon into 24 paper-lined muffin-pan cups.
• Bake 18 to 21 min. or until toothpick inserted in centers comes out clean. Cool 10 min. Remove cupcakes from pans to wire racks; cool completely.
• Meanwhile, cover baking sheet with parchment. Melt white chocolate as directed on package. Dip rounded end of each cookie half, one at a time, partway into melted chocolate. Place on prepared baking sheet. Top each with 2 candy eyes. Let stand until chocolate is firm.
• Beat butter, sugar and 1/4 cup (4 Tbsp.) milk in large bowl with mixer until creamy. Spoon half the frosting into separate bowl.
• Add peanut butter to 1 bowl of frosting; beat with mixer until blended. Beat cocoa powder and remaining milk into remaining bowl of frosting. Refrigerate both bowls of frosting until ready to use.
• Spoon each frosting into separate disposable pastry bag; cut tips off bottoms of bags. Place both bags of frosting into third pastry bag fitted with large star tip. Use to pipe frosting onto cupcakes, squeezing bags gently so both frostings swirl together onto each cupcake.
• Top with sprinkles. Insert cookie half ghosts into frosting.