01 - Preheat the oven to 350°F. Line a 9-inch square baking pan with parchment paper, leaving overhang for easy removal.
02 - Combine crushed chocolate cookies and melted butter in a medium bowl. Mix until evenly moistened, then press firmly into the bottom of the prepared pan. Bake for 8 minutes and set aside.
03 - Beat cream cheese and sugar in a large bowl until smooth and creamy. Add egg, egg yolk, vanilla extract, peppermint extract, and salt; beat until fully combined.
04 - Mix in sour cream and food coloring until smooth and evenly colored throughout the mixture.
05 - Gently fold mini chocolate chips into the cheesecake batter until evenly distributed.
06 - Pour cheesecake filling over the pre-baked crust and smooth the top. Bake for 30-32 minutes until the center is just set and edges appear slightly puffed.
07 - Cool completely at room temperature, then refrigerate for at least 2 hours until fully chilled before serving.
08 - Lift cheesecake from pan using parchment overhang. Cut into 16 bars and serve chilled.