Prep: Preheat your oven to 350℉. Spray a 9x9 metal pan with nonstick spray and line with parchment paper.
Make the Cookie Base: Melt the butter in a large mixing bowl. Whisk in the cocoa powder and espresso powder, then the sugars. Add the eggs, vanilla, and peppermint extract and whisk until smooth and combined, about 30-45 seconds. Stir in the dry ingredients, making sure to get any dry bits hiding in the bottom of the bowl.Tip: Don't fret if the dough seems dry while mixing in the dry ingredients - this will take a bit of elbow grease, or you can use a mixer for this part. I promise the dough isn't dry and it will all incorporate! 14 and 1/2 tbsp tbsp salted butter, 1/2 cup + 1 tbsp cocoa powder, 1/2 tsp espresso powder, 3/4 cup brown sugar, packed, 3/4 cup granulated sugar, 2 large eggs, at room temperature , 1 and 1/2 tsp vanilla extract, 1/2 tsp peppermint extract, 2 and 2/3 cups all-purpose flour, spooned & leveled, 1 tsp baking powder, 1 tsp baking soda, 1/2 tsp salt
Bake: Press the dough into your prepared pan in an even layer. Bake for 16 minutes. The edges will be slightly raised, and the center will have a slight wobble when you move the pan. Don't over bake these! They will set up to the perfect soft-baked texture as they cool. Let the bars cool in the pan on a wire rack until completely cooled. Make the Hot Fudge: Add the chocolates, evaporated milk, and sugar to a medium saucepan. Heat over medium heat until it just reaches a low boil, stirring constantly. Once it reaches the low boil, remove it from the heat and stir in the butter, vanilla, and peppermint. The sauce will thicken more as it cools.Let the hot fudge cool a tad, so it's not super hot, then pour 2 cups (540 grams) of the hot fudge over the cooled bars. Place in the fridge for a few hours or overnight, until the hot fudge is set. Storing Leftover Hot Fudge: Leftover hot fudge can be stored in an airtight container in the fridge for up to 2 weeks and reheated gently. 1 cup dark chocolate chips, 1 cup semi-sweet chocolate chips, one 12 ounce can evaporated milk, 1/2 cup granulated sugar , 1 and 1/2 tsp vanilla extract , 1 tsp peppermint extract, 1 tbsp salted butter
Make the Meringue: Make the meringue by following my meringue recipe here. The directions in this post are very thorough so it's easier if you just visit that page! Once the meringue is whipped, use a toothpick to dot a little bit of red food coloring in, and gently swirl it in with a spatula. Pile the meringue on top of the chilled hot fudge layer and spread it with the back of a spoon, making swoops and swirls as you go. Sprinkle some crushed candy cane pieces on top if desired. 4 large egg whites, at room temperature , 1 cup granulated sugar , 1/2 tsp cream of tartar, 1/8 tsp salt, 2 tsp vanilla extract, red food coloring, crushed candy canes
Serve & Store: Once the meringue is added to the bars, they can be chilled in the fridge for up to 24 hours more before serving, or you can slice and serve after a short 30 minute rest in the fridge. Store leftovers in an airtight container in the fridge for 3-4 days.
Make-Ahead Tips: Bars: Bars can be baked, cooled to room temperature, and stored (covered well) at room temperature for up to 24 hours before adding hot fudge and meringue.Hot Fudge: Make the hot fudge up to 2 days ahead and store in the fridge. Gently reheat so it's pourable when ready to use. Meringue: This cannot be made ahead and stored on its own. But, it can be made and added to the bars up to 24 hours before serving.