Fit the paddle attachment to your stand mixer and lock in the bowl. Using a medium-high speed, mix the butter, and sugar until it is one consistency. Then add the cream cheese. Cream this until the mixture is light and fluffy. This will take about 5 to 8 minutes. Make sure to scrape the bowl about halfway through.
Add the vanilla extract and egg and mix until uniform throughout. Again, make sure to scrape the bowl partway through.
Mix in the dry ingredients: flour, baking powder, cocoa powder, and salt. You can choose to whisk these together in a separate bowl if you wish but its not necessary especially with a stand mixer. Again, scrape the bottom at least once partway through to ensure everything is mixed.
Cover and chill in the refrigerator for at least 30 minutes.
When the chilling is done, preheat oven to 350℉. In one bowl measure out 1 cup of powdered sugar. In another bowl, measure out 1 cup of granulated sugar (optional). Rolling in granulated sugar before rolling in powdered sugar will make the "crinkle" part of the cookie more vibrant but it does add a little bit of the granulated sugar crunch to each bite.
Using a baking sheet(s) lined with parchment paper, portion out the cookie dough using the cookie scooper or estimate about 2 tablespoons size. Roll each dough ball in granulated sugar (optional) and then powdered sugar before placing on the baking sheet(s) with enough room to spread.
Bake in the oven at 350℉ for 10 to 12 minutes until the edges set.
Remove from the oven, let cool, and enjoy!
