First, preheat oven to 350 degrees Fahrenheit. Line a baking pan with parchment paper.

In the bowl of a stand mixer, add cold butter, sugar and brown sugar. Mix on high for 2 to 3 minutes, until completely creamy. Mix until no clumps of butter remain.

Add in vanilla and egg. Stir to combine.

Then, add in baking powder, cocoa powder and melted chocolate. Stir to combine.

Add in the flour. Stir to combine.

Add about 3 tablespoons of white sugar to a shallow bowl. Roll cookie into 1 inch balls. Roll each ball thoroughly in the white sugar.

Place on baking pan at least 2 inches apart. These cookies spread slightly.

Bake for 10 to 11 minutes or until cookies look set around the edges.

Remove from oven. Immediately press an unwrapped Hershey kiss in the middle of each cookie.

Finally, allow cookies to fully cool before eating.