Prepare dry ingredients: Whisk flour, cocoa powder, baking powder, baking soda, and salt in a medium bowl. Set aside.
Mix wet ingredients: In a large bowl, whisk granulated sugar, brown sugar, eggs, vegetable oil, and vanilla extract until smooth. Stir in melted chocolate chips.
Combine mixtures: Gradually fold dry ingredients into wet until just combined.
Chill dough: Cover and refrigerate dough for at least 2 hours (up to 24 hours).
Preheat oven: Set oven to 350°F (175°C). Line two baking sheets with parchment paper.
Roll in sugar: Scoop tablespoon-sized dough portions, roll into balls, and coat generously in powdered sugar.
Bake: Place balls 2 inches apart on baking sheets. Bake for 10-12 minutes until cookies spread and crack.
Cool: Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack.