Preheat oven to 350 degrees and prepare a cookie sheet with a parchment paper.
In a mixing bowl, fitted with the paddle attachment, cream butter with the granulated and dark brown sugars.
Add egg and thoroughly combine, then add the greek yogurt and vanilla.
In a medium bowl, whisk together flour, cocoa, baking powder, baking soda, and salt. Gradually add to butter mixture.
Stir in the chocolate chips. Using rounded tablespoons, drop on prepared baking sheet about 2 inches apart.
Bake for 12 minutes and be sure not to over bake. They should look slightly moist when you take them out of the oven, as they will set when they're cooling.
Whipped Cream
In a mixing bowl fitted with a wire whisk, pour in the whipping cream. Add vanilla seed from the scraped vanilla bean.
Add peppermint extract. Beat until soft, somewhat stiff peaks are formed while gradually adding the sugar.
Spread a large tablespoon of whipped cream on the flat half of one cookie, then top with another cookie.
On a small plate, place crushed peppermint candies and roll the outer edges of the cookie so it is covered with peppermint.