Stir together dry ingredients (all-purpose flour, cocoa powder, baking powder, salt) in a medium mixing bowl. Set aside.
To a large mixing bowl, add the sugar, oil and eggs. Use a large spoon or mixer on low speed to combine. Mix until eggs are fully combined, about 1 minute. Stir in the vanilla extract.
With the mixer running, slowly mix in the dry ingredients about one cup at a time. Once all of the dry ingredients are added you will have a soft but malleable dough.
Cover the bowl and refrigerate for 30 minutes. Preheat the oven to 350 degrees F.
After 30 minutes, remove the dough from the fridge. Use a spoon (like the kind you eat with, not a tablespoon) to measure out pieces of dough. Roll into roughly ping-pong sized balls to make 24 cookies.
Transfer the balls, one or two at a time, to the bowl of powdered sugar. Coat thoroughly in the powdered sugar. You should not be able to see any of the dough.
Line the cookies up on a parchment paper lined cookie sheet, leaving one inch between cookies. Bake at 350 for 8-10 minutes. Left rest for 5 minutes after removing from the oven, then transfer to a cookie rack to cool.
All-purpose flour: I recommend using the spoon and level method to measure flour. To do this, spoon flour into the measuring cup and wipe off excess with the back of a knife.
Canola oil: Can also use other neutral oils like vegetable oil. Olive oil works but may have a slightly different flavor. Coconut oil works only if completed melted.
Storage: For best quality, keep in a closed container at room temp for 3-4 days. Any leftovers can be frozen.
To freeze cookies: Let cookies cool to room temp. Then place in a freezer safe container. They shouldn't stick together, but you can place layers of parchment paper between the cookie if desired. Keep frozen for up to 3 months.