Preheat your oven to 350°F (175°C). Line several baking sheets with parchment paper or silicone mats.
In a large bowl, whisk together the eggs, vegetable oil, granulated sugar, and vanilla extract until well combined and smooth.
In a separate medium bowl, whisk together the flour, cocoa powder, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing with a wooden spoon or spatula until just combined. The dough will be thick and sticky.
For easier handling, cover the bowl and chill the dough for 30 minutes to an hour.
Place the ½ cup of powdered sugar in a shallow bowl. Scoop rounded tablespoons of dough and roll them completely in the powdered sugar until fully coated. This creates the signature crinkle!
Place the coated dough balls about 2 inches apart on your prepared baking sheets. Bake for 8 minutes. The cookies will puff up and then crinkle beautifully. They will look slightly soft in the center but will set as they cool.
Let the cookies cool on the baking sheets for 5 minutes before carefully transferring them to a wire rack to cool completely. Do not frost warm cookies!