1-Step 1: Prepare the Dough
Melt the 12 oz semi-sweet baking chocolate and 1/2 cup unsalted butter in a microwave-safe bowl, heating in 30-second intervals and stirring until smooth. Let it cool slightly to avoid cooking the eggs later. In another bowl, sift together 1 1/2 cups all-purpose flour, 1/4 cup unsweetened cocoa powder, 1 1/2 teaspoons baking powder, and 1/2 teaspoon salt; whisk to combine thoroughly.

Using an electric mixer, blend 1 1/4 cups packed light brown sugar, 3 large eggs, 1 teaspoon peppermint extract, and 1 teaspoon vanilla extract until fluffy. Then, mix in the cooled chocolate mixture on low speed. Gradually add the flour mixture until just combined. Cover the dough and chill it for at least 1 hour until firm chilling cookie dough like this helps with shaping and baking.

2-Step 2: Bake the Cookies
Preheat your oven to 325°F (162°C) about 15 minutes before the dough is ready. Scoop the dough into 1 heaping tablespoon portions, shape them into balls, and place them 2 inches apart on parchment-lined baking sheets. Keep any unused dough chilled to maintain its texture.

Bake for about 9 minutes until the cookies are slightly under-baked; they should be soft in the center. This step is crucial for that gooey, hot chocolate-like feel. Have you noticed how under-baking keeps cookies chewy? It’s a game-changer for treats like these.

3-Step 3: Add the Marshmallows
Remove the cookies from the oven and quickly cut the 24 large marshmallows in half using kitchen scissors. Place one marshmallow half, cut side down, on each cookie. Pop them back in the oven for 2-3 more minutes until the marshmallows melt slightly, then gently press them to flatten.

Let the cookies cool on the pan for a few minutes before transferring to wire racks set over baking sheets. This cooling process helps them set without becoming too firm perfect for that melty experience.

4-Step 4: Make the Icing
While the cookies cool, sift 2 cups powdered sugar and 1/4 cup unsweetened cocoa powder together. In a saucepan, heat 4 tablespoons unsalted butter and 1/4 cup heavy cream over medium heat until the butter melts and the mixture simmers; remove from heat.

Pour the sifted sugar and cocoa into the warm mixture and whisk until smooth, then stir in 1/4 teaspoon peppermint extract. If needed, thin with hot water or thicken with more powdered sugar to get the right consistency for drizzling.

5-Step 5: Finish and Serve
Once the cookies are fully cooled, spoon or drizzle the icing over them. Immediately sprinkle with crushed peppermint candies before the icing sets. The whole process, from prep to enjoyment, takes about 1 hour and 10 minutes, with 35 minutes for prep and 35 for cooking.