In a medium mixing bowl, stir together cocoa powder, sugar, and vegetable oil until well combined. Add the eggs one at a time, mixing until each is fully incorporated, then stir in the vanilla extract.
½ cup unsweetened cocoa powder, 1 cup white sugar, ¼ cup vegetable oil, 2 large eggs, 1 teaspoon vanilla extract
In a separate bowl, whisk together flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture, stirring until fully combined.
1 cup all-purpose flour, 1 teaspoon baking powder, ¼ teaspoon salt
Cover the dough and refrigerate for at least 4 hours.
Preheat your oven to 350°F (175°C). Roll the chilled dough into 1-inch balls, then roll each in confectioners' sugar to coat. Place the dough balls about 1 inch apart on a lined baking sheet.
¼ cup confectioner's sugar
Bake for 10-12 minutes, until cookies are set but still soft in the center. Let them cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely. Serve and enjoy!