Make the cupcakes: Preheat the oven to 350 degrees F and line a 12-cup muffin pan with paper liners. Whisk the flour, baking powder and salt in a medium bowl. Beat the butter in a large bowl with a mixer on medium-high speed until smooth, about 1 minute. Add the granulated sugar and beat until creamy, about 4 more minutes. Beat in the eggs, one at a time, then the vanilla. Reduce the mixer speed to low and beat in the flour mixture in three batches, alternating with the milk. Increase the mixer speed to medium high and beat until just combined.
Divide the batter among the muffin cups. Bake until the tops spring back when gently pressed, 20 to 25 minutes. Transfer the cupcakes to a rack and let cool 5 minutes in the pan, then remove to the rack to cool completely.
Meanwhile, make the bows: Line a baking sheet with parchment paper. Put the red candy melts in a microwave-safe bowl; microwave in 30-second intervals, stirring, until smooth. Transfer to a resealable plastic bag and snip a small corner. Pipe 2 1/2-inch bows onto the parchment (make a few extra bows in case some break). Put the white candy melts in a microwave-safe bowl; microwave in 30-second intervals, stirring, until smooth; let cool slightly. Transfer to another resealable plastic bag and snip a small corner. Pipe white dots on the bows; let set, 15 to 20 minutes.
Make the topping: Finely grind 24 cookies in a food processor; transfer to a small bowl and set aside. Wipe out the food processor. Make the frosting: Put the chocolate in a microwave-safe bowl; microwave in 30-second intervals, stirring, until smooth. Pulse the butter, confectioners' sugar, melted chocolate, cocoa powder, milk and vanilla in the food processor until smooth. Spread on the cupcakes.
Dip the cupcakes in the cookie crumbs, pressing to adhere. Separate the remaining 12 sandwich cookies; arrange 2 halves upright on each cupcake for the ears, pressing the cookies into the frosting. Carefully lift the bows off the parchment; lean them up against the cookies.