Melt the chocolate in a double boiler, or a heat proof bowl set over a pot of simmering water. Stir occasionally, until smooth. Set aside.

Meanwhile, whisk together the flour, cocoa, baking powder, espresso powder, and salt in a bowl. Set aside.

In the bowl of an electric mixer, beat together the butter and sugars until combined, about 1 minute. The sugar will still look granular.

Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract. With the mixer on low speed, add the melted chocolate in a steady stream. Scrape down the bowl.

Add the flour mixture and mix on low speed until just combined. Stir in 1 cup of the Andes mints. Allow the dough to rest, covered with saran wrap, at room temperature for 30 minutes. The dough will be like the consistency of playdough.

Preheat the oven to 350 degrees. Line 2 baking sheets with parchment paper or silicone baking mats.

Use a standard (Tablespoon) sized scoop to scoop balls of dough onto the prepared pans, spacing them about 2 inches apart.

Bake for 8-9 minutes, or until cookies are set on the edges, but still soft and puffy in the middle. Remove the cookies from the oven, and gently press additional Andes mints into the top. Allow the cookies to set up on the pan for 5-10 minutes, then transfer to a cooling rack to cool completely. If desired, you can swirl the melted Andes mints a bit before they cool.