Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a medium saucepan, melt the chopped baking chocolate and 1 cup of unsalted butter over low heat, stirring until smooth. Remove from heat and let it cool slightly.
Step 3: In a large mixing bowl, whisk together the melted chocolate mixture with 1 ½ cups of granulated sugar. Add in the 3 eggs, mixing well after each addition. Stir in vanilla extract and salt.
Step 4: Sift in the cocoa powder and 1 cup of flour. Gently fold until just combined.
Step 5: In another bowl, beat together 1 cup of unsalted butter and 1 ½ cups of sugar until fluffy. Add in 1 egg, mixing well. Stir in vanilla and peppermint extract, and add food coloring if using.
Step 6: In a separate bowl, whisk together baking soda, salt, and 2 cups of flour. Gradually add to the wet mixture, mixing until just combined. Fold in chocolate chips.
Step 7: Spread the brownie batter in the prepared baking pan, then spoon the cookie dough on top. Bake for 25-30 minutes or until a toothpick comes out with a few moist crumbs.
Step 8: Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Slice into squares and enjoy!
