How to Make It
Pulse candy canes and chocolate kisses in a food processor until finely chopped, 10 to 14 times. Set aside. Bring 1 inch of water to a simmer in a medium saucepan over medium. Place chopped white chocolate in a medium heatproof bowl, and place over simmering water, ensuring base of bowl does not touch water. Heat, stirring often, until chocolate is melted and smooth, about 6 minutes.
Remove from heat; stir in candy cane mixture and 1 drop of food coloring gel until incorporated. Pour chocolate mixture onto a parchment paper–lined baking sheet; spread into a 12- x 10-inch rectangle. Freeze, uncovered, until firm and set, about 2 hours. Break or cut bark into 1/2-inch pieces. Store in an airtight container in freezer until ready to use, up to 1 week.
Stir together flour, red Dutch-process cocoa, cocoa blend, crushed wafer cookies, baking powder, and salt in a large bowl; set aside.
Add butter and sugar to bowl of a heavy-duty stand mixer fitted with a paddle attachment. Beat on medium speed until light and fluffy, about 5 minutes. Add melted semisweet chocolate, and beat until combined. Add eggs, 1 at a time, beating until well combined after each addition. With mixer running on low speed, gradually add flour mixture, beating until just incorporated. Stir in chocolate chips. Wrap dough tightly in plastic wrap, and refrigerate at least 4 hours or up to 3 days.
Preheat oven to 375°F. Using your hands, roll dough into 24 balls (about 3 ounces each). Place 6 dough balls 2 inches apart on a parchment paper–lined baking sheet (keeping remaining dough balls chilled). Bake in preheated oven until cookies are set but still soft, 12 to 16 minutes. Remove from oven, and immediately top cookies with 6 to 8 peppermint bark pieces, slightly inserting edges of bark into warm cookies to hold in place. Let cookies cool on baking sheet 5 minutes. Serve warm, or transfer to a cooling rack to let cool completely, about 30 minutes. Repeat with remaining cookie dough balls and peppermint bark.