Make the cupcake cones: Preheat the oven to 350 degrees F. Place 1 ice cream cone in each cup of a 12-cup muffin pan and set aside.
Melt the butter in a small saucepan over low heat. Pour over the chocolate in a small heatproof bowl; let sit a minute to melt, then stir together and set aside.
In a large bowl, combine the flour, sugar, cocoa powder, baking powder, salt and eggs. Stir to break the eggs, then stir with the dry ingredients until the batter is smooth. Add the chocolate-butter mixture and stir until well combined.
Spoon the batter into a piping bag and pipe into the cones, dividing it equally among the cones, no more than three-fourths full. Bake until a cake tester or toothpick inserted into the center of the cake comes out clean and the cakes spring back to the touch, 20 to 25 minutes. Remove from the oven and let cool completely.
Beat together the butter, confectioners' sugar and vanilla in a large bowl with a handheld mixer on medium-high speed, until light and fluffy, 3 to 5 minutes. Divide the frosting into bowls and tint with the food coloring, as desired. Transfer each colored frosting to a piping bag fitted with a star tip. Pipe a swirl of frosting onto each cupcake cone and decorate with a piece of cookie and sprinkles.