Preheat the oven to 350˚ F. In the bowl of an electric mixer, combine the butter and sugar.
Beat together on medium-high speed until light and fluffy, 2-3 minutes. Blend in the eggs one at a time, scraping down the bowl as needed. Mix in the cocoa powder until well blended. I LOVE the Hershey's Dark Cocoa Powder, but it can be hard to find. Regular cocoa powder works just fine in this recipe.
Add the flour, crushed candy canes, salt and baking powder to the bowl and mix on low speed just until incorporated.
Fold in the chocolate chips and peppermint chips with a spatula. The dough is very thick. So thick that at the end you may have to knead it almost as you would bread to incorporate everything.
Now it's time to make your "stuffed" cookies. I scooped out two balls of dough with my cookie scoop and then put together my minty chocolatey cookie sandwich if you will.
Completely cover your peppermint bark by working the top and bottom pieces of dough together.
If you stuff all of your cookies, you will probably get about 12 stuffed cookies. Bake for approx 12-16 minutes for stuffed cookies, and 8-12 for regular cookies. These cookies are delicious when slightly underdone and still warm, but if you are packing them up for holiday cookie trays you might want to go with the slightly longer baking time to make them easier to handle. Let cool on baking sheet for approx 5-10 minutes then transfer to a wire rack to cool completely.