01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt. Set aside.
03 - In a large bowl, beat butter, brown sugar, and granulated sugar together until light and creamy, about 2-3 minutes.
04 - Add egg, egg yolk, vanilla extract, milk, and red food coloring. Mix until well combined.
05 - Gradually add dry ingredients to wet ingredients, mixing until just combined.
06 - Fold in white chocolate chips and chopped Oreo cookies until evenly distributed.
07 - Using a medium cookie scoop or tablespoon, drop rounded balls of dough onto prepared baking sheets, spacing about 2 inches apart.
08 - Bake for 10-12 minutes, or until edges are set and centers look slightly underbaked.
09 - Allow cookies to cool on baking sheet for 5 minutes before transferring to wire rack to cool completely.