In a large bowl, mix flour, baking powder, sugar, cocoa, and salt. Whisk to blend.
In another bowl, add all wet ingredients and mix well.
Slowly stir the liquid mixture into the flour mixture until fully incorporated.
Cover the dough with plastic wrap and refrigerate until chilled.
Scoop chilled dough into small balls and roll in confectioner’s sugar. I found that it was easy to just scoop out a chunk of dough, sprinkle some powdered sugar on it, and then roll it into a ball. Use a glass to smoosh the balls flat to about 1 inch thickness.
Place cookie balls on a parchment paper covered baking sheet. Bake in 350F oven for 10-12 minutes.
They should still be a bit soft, but fully cooked all the way through.
Allow to cool on the baking sheet for a minute or two before moving them to a cooling rack.