This recipe for mint chocolate cupcakes starts about 1/2 way through, with the cake mix already made, and adding cocoa powder to the mix. I have to wonder if it'll create a chocolatey enough flavor, but maybe you can check to see if there are other chocolate cupcake recipes that work better for you.
Maybe even just get a chocolate cake mix from a box and work with that.
Though it wasn't the original name of the recipe, I dubbed this the “dinner mint” chocolate mint cupcake recipe because there's a total of THREE mints used! Place one on the bottom, then some batter, then another on top. Top with batter again, and bake. After that, another mint goes on top. Yup, three of them.
After placing your third mint on top of the baked (and cooled) cupcake, it's time to frost. Mint buttercream frosting is used, though no specific recipe is given. From all of the recipes I've seen, it can be made from butter, sugar, green dye, and peppermint extract (beaten until creamyO
Though not necessary, heating some chocolate melts or chocolate chips is a good way to top your treats with a design. Here, a piping tool with a fine tip is used to draw a pattern on the cupcake, then topped with powdered sugar for presentation.
You can see the full video below and watch the cupcake making in action. There's no link to a full recipe, but in the description of the video you'll see a cake and buttercream recipe.