1-Preheat and prepare: Preheat oven to 350°F and line baking sheets with parchment paper.

2-Whisk dry ingredients: Whisk together flour, cocoa powder, baking soda, and salt in a medium bowl.

3-Cream butter and sugar: Beat softened butter and granulated sugar until light and fluffy, about 2 minutes.

4-Add egg and coloring: Beat in egg, vanilla extract, and red gel food coloring until uniform.

5-Alternate flour and sour cream: With mixer on low, alternately add flour mixture and sour cream, mixing just until incorporated.

6-Fold in chips: Gently fold in white chocolate chips, reserving some for topping.

7-Chill dough: Cover dough and refrigerate at least 30 minutes to prevent spreading.

8-Portion cookies: Scoop rounded tablespoons (about 30g each) onto prepared sheets, spacing 2 inches apart.

9-Bake: Bake for 6 minutes, rotate pans, then continue baking until edges are set and centers look soft, about 11-14 minutes total.

10-Add extra chips: Immediately press reserved white chocolate chips onto hot cookies.

11-Cool: Let cookies cool on baking sheet 5 minutes, then transfer to wire rack to cool completely for crispy edges and soft chewy centers.