Preheat oven to 350 degrees Fahrenheit and line two baking sheets with parchment paper.
In a medium bowl, whisk together flour, black cocoa powder, baking powder, and salt. Set aside.
In a large bowl, cream together softened butter, brown sugar, and granulated sugar with an electric mixer until fluffy, about 2 minutes.
Add egg yolks and vanilla, mixing until pale and fluffy, about 1 minute.
Add dry ingredients to butter mixture and mix on low speed until combined.
Scoop dough into 16 portions (2 tablespoons each), flatten slightly, and place a frozen cheesecake ball in the center. Enclose the cheesecake ball with cookie dough and roll into a ball.
Roll cookie dough balls in black cocoa sugar and place on prepared baking sheets. Bake 6 cookies at a time for 10-11 minutes.
Use a large, round cookie cutter to shape cookies immediately after removing from the oven.
Let cookies cool on baking sheet for 10 minutes, then transfer to a wire rack to cool completely before serving. Enjoy!