In a small mixing bowl, combine cream cheese, granulated sugar, and vanilla extract. Beat until pale and fluffy, about 2-3 minutes. Scoop into 16 equal portions and freeze for at least 30 minutes.

In a medium bowl, whisk together flour, black cocoa powder, baking powder, and salt. Set aside.

In a large mixing bowl, beat softened butter, light brown sugar, and granulated sugar together until fluffy, about 3-4 minutes.

Add egg yolks and vanilla extract to the butter-sugar mixture. Mix until pale and fluffy, about 2 minutes.

Gradually mix in the dry ingredient mixture until just combined.

Scoop about 2 tablespoons of dough, flatten it, place a frozen cheesecake ball in the center, and enclose it with the dough. Repeat for all portions.

Roll each cookie ball in a mixture of granulated sugar and black cocoa powder until evenly coated.

Preheat oven to 350°F (175°C). Bake cookie balls for 10-11 minutes until edges are set.

Cool cookies on the baking sheet for 10 minutes before transferring to a wire rack.