In a large mixing bowl, combine unsweetened cocoa and granulated sugar. Use a whisk to blend them well until there are no lumps. The mixture should resemble dark brown sand.
Add vegetable oil and eggs to the cocoa mixture. Mix well using a spatula or electric mixer until the batter is cohesive and glossy. Make sure everything is fully incorporated.
Next, add vanilla extract, flour, baking powder, and salt. Stir until the dough forms. It should be thick and slightly sticky but not too wet.
Transfer the dough into an airtight container. Refrigerate for 2 to 3 hours, or ideally overnight. This step helps the flavors develop and makes the dough easier to handle.
Once ready to bake, preheat your oven to 350 degrees F (175 degrees C). Prepare your baking sheets by lining them with parchment paper.
Take about 2 teaspoons of chilled dough and roll it into a ball. Make sure the balls are uniform for even baking.
Drop the dough balls into powdered sugar. Roll them around until they are completely coated. Ensure you have a generous amount of sugar to create a nice crust.
Place the sugar-coated balls on the prepared baking sheet, spacing them about 2 inches apart. This allows room for spreading as they bake.
Bake in your preheated oven for about 10 to 12 minutes. Keep an eye on them; they should puff up and crack on top but remain soft inside.
Once baked, allow the cookies to cool on the baking sheet for 1 minute. Then, carefully transfer them to a wire rack to cool completely. This helps them firm up while retaining their chewy center.
