Preheat oven to 350°.
While the oven is preheating make the cookie dough. Cream together the butter and sugar until light and fluffy.
Scrape the sides, add in the eggs and vanilla extract. Beat until mixed.
Scrape the sides and add in the flour, & baking powder. Mix until thoroughly combined.
Scoop out a generous 1/3 cup of dough and roll into a ball. Repeat with remaining dough.
Flatten the cookie dough so it looks similar to what your finished cookie will look like. It should.be about 1/2 inch thick. The cookies will spread just a little bit, not much. Repeat with remaining dough.
Arrange on a cookie sheet. I tend to only put 6 cookies per pan.
Bake at 350° for 12-15 minutes or until the centers of the cookies have puffed up and are no longer glossy.
While the cookies are cooling, make the frosting, by whipping the butter and cream cheese until smooth.
Add the powdered sugar, one cup at a time.
Add in the cocoa powder.
Add the vanilla.
Add milk 1 tbsp at a time until you've reached your desired consistency.
Add the frosting to a piping bag fit with a large closed star attachment. Pipe the frosting onto the warm cookies in a spiral, starting in the center of the cookie working your way out.
Sprinkle with chocolate sprinkles on top of the frosting. Serve warm.