Preheat your oven to 350℉. Pit and prep your cherries if necessary. Line your baking sheet with parchment paper.
Gently blot some moisture off of your pitted cherries to avoid letting the dough get TOO moist.
In your mixer, beat together the butter and sugar until creamy and fluffy.
Add in the egg and vanilla and beat to combine.
Mix the flour, cocoa powder, and baking powder in a small bowl, then add to the butter mixture. Add in the cherries, and continue to mix until combined. You'll mash the cherries somewhat and it will be difficult to fully combine it all, but it will eventually come together.
Divide the dough into small 1.5" balls (about 2 tbsp of dough each) and place them about 2" apart on your baking sheet. They won't spread much but they do spread a little.
Indent each cookie with your thumb and add one of the pitted whole cherries.
In your sauce pan, over medium heat, combine the chocolate chips and condensed milk. Heat and stir until the chocolate is melted and fully mixed. Drizzle this over your cookies.
Bake for 10-12 minutes. When done, allow to mostly cool before serving.