Whisk the dry ingredients. In a medium bowl, whisk 1 1/2 cups all-purpose flour, 1/2 cup unsweetened cocoa powder, 1 1/2 teaspoons baking powder, and 1/2 teaspoon salt. If using espresso powder, whisk in 1 teaspoon here.
Mix the wet ingredients. In a large bowl, whisk 2 large eggs, 1/2 cup granulated sugar, 1/2 cup packed light brown sugar, 1/3 cup neutral oil, and 2 teaspoons vanilla extract until smooth and slightly thickened, about 30–45 seconds.
Combine. Add the dry ingredients to the wet and fold with a spatula just until no dry streaks remain.
The dough will be thick and sticky—more like brownie batter than standard cookie dough.
Chill the dough. Cover and refrigerate for at least 2 hours, or up to 24 hours. Chilling firms the dough and helps create the bold crinkle effect.
Prep to bake. Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
Place about 1/3 cup granulated sugar in one shallow bowl and 1 cup powdered sugar in another.
Portion and coat. Using a tablespoon or small scoop, portion 1–1 1/2 tablespoon mounds. Roll quickly into balls. Toss each ball in granulated sugar first, then in powdered sugar, coating generously. Thick coverage means bolder crinkles.
Arrange and bake. Place on prepared sheets, spacing 2 inches apart.
Bake 10–12 minutes, until tops are crackled and edges are set but centers are still soft. They should look slightly underbaked.
Cool. Let cookies rest on the sheet for 5 minutes, then transfer to a rack to cool completely. They’ll firm up as they cool while staying fudgy inside.