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.
03 - Press mixture firmly into the bottom of the prepared pan to form an even crust. Bake for 8 minutes. Remove from oven and set aside.
04 - Beat cream cheese and sugar in a large bowl until smooth and creamy.
05 - Add egg, egg yolk, vanilla extract, peppermint extract, and salt. Beat until fully combined.
06 - Mix in sour cream and food coloring if using until mixture is smooth and evenly colored.
07 - Gently fold in mini chocolate chips until evenly distributed.
08 - Pour cheesecake filling over pre-baked crust and smooth top. Bake for 30-32 minutes until center is just set and edges appear slightly puffed.
09 - Cool completely at room temperature, then refrigerate for at least 2 hours until fully chilled.
10 - Lift cheesecake from pan using parchment overhang. Cut into 16 bars and serve.