In the bowl of a stand mixer fitted with the paddle, cream together the sugar, light brown sugar, oil, and melted butter on a medium-low speed until all the ingredients are mixed together.

Add the cocoa powder (and espresso powder) to the mixture and mix on a low speed until completely mixed in.

Scrape down the sides of the bowl and add the in eggs one at a time, scraping down the sides of the bowl after each addition. Then add the vanilla and mix until combined.

In a separate bowl, stir together flour, baking powder, and salt. Add to cocoa mixture, mixing on a low speed until all the flour is mixed in.

Cover the dough with plastic wrap and refrigerate for at least 1-2 hours.

Preheat oven to 350°F and line cookie sheet(s) with parchment paper.

Using a cookie scoop, scoop the cookie dough into a ball and roll it between the palms of your hands to create a smooth cookie dough ball.

Place the cookie dough balls 2 in. apart from each other on a cookie sheet.

Bake the cookies for 12-14 minutes, allow the cookies to cool completely before adding the peppermint buttercream.

Place the softened butter into the bowl of a stand mixer fitted with the paddle attachment.

Cream the butter at a medium speed until it is pale in color.

Add the powdered sugar and mix on a low speed until it’s all combined. Then mix at a high speed until the mixture is white and fluffy. Scrape the sides of the bowl to ensure that all the butter has been mixed in properly.

Finally, add the vanilla extract, heavy cream, and peppermint extract to the buttercream and mix at a medium-low speed until combined.

Pipe the buttercream onto the cookies or spread the buttercream on top using an offset spatula.

In a microwave safe bowl, microwave the heavy cream in 15-30 second intervals until its hot.

Pour the hot heavy cream over the dark chocolate.

Mix the heavy cream and chocolate together until its smooth and there are no lumps.

Drizzle the dark chocolate ganache over the cookies and top with peppermint pieces!

Enjoy :)