Rolling these black cocoa crinkle cookies in two types of sugar before baking gives you an even spread of crinkles on top. Inside, they're delicate and decadent, with a light, chewy texture that's as deep, dark, and inky black as the night sky.
Mise en place. Get your ingredients to the right temperatures, measure them properly, and make sure you know where your vanilla and powdered sugar are!
Mix the dry ingredients. Combine flour, baking powder, baking soda, and salt in a small bowl. Set aside.
Bloom black cocoa. Measure black cocoa into a large mixing bowl. Pour the boiling water over the cocoa and mix with a spatula until a thick paste forms. Scrape everything off the spatula into the bowl and set the spatula aside.
Whisk in sugar, egg, vanilla, oil. Switch to a whisk and add the sugar, egg, vanilla bean paste, and oil all at once. Whisk vigorously for 60 seconds until everything is combined and very smooth. This is a very thick mixture, it helps to whisk in small sections at first, gradually incorporating more and more from the sides of the bowl until it all combines.
Sift in the dry ingredients. Use a wire mesh strainer or sifter to sift the dry ingredients into the wet ingredients. Switch back to the spatula and gently fold and stir until all the flour is combined. The flour is sneaky here and sometimes hides inside the cookie dough — use the edge of spatula to periodically draw a line down the middle of the mixing bowl to "cut" the dough in half in case anything is hiding inside!
Cover and chill 4 hours or overnight. You can scoop the cookies in as little as two hours after chilling, but the dough is much much much easier to work with after at least 4 hours when the oil has firmed up. You can also leave it in the fridge overnight.
Preheat oven to 350°F. Line two sheet pans with parchment paper or silicone mats. Assemble your cookie coating stations: Fill a small bowl with granulated sugar, and another with powdered sugar. Arrange them between the cookie dough bowl and the cookie sheets so you can easily move the dough from one bowl to the other and right onto the sheet pans.
Scoop and roll. Use a #40 (1½ tablespoon) cookie scoop to drop balls of dough into the granulated sugar. Scrape the scoop flat against the side of the bowl to remove any excess dough so you get uniformly sized cookies. Roll the cookie dough balls around in the sugar, then roll them in powdered sugar. Be generous with the sugar coating! Arrange the cookie dough balls in rows on parchment lined sheet pans about 3 inches apart. You can usually fit about 12 on a half sheet pan.
Bake for 10 minutes. The cookies will be puffed up and very soft when done, but will sink down as they cool. They are VERY soft and fragile. Let them cool on the sheet pan for 10-15 minutes, then transfer carefully to cooling rack to finish cooling.
To help the dough release from the cookie scoop easily, give the scoop a light spritz with non-stick spray before scooping.
To quickly bring an egg to room temperature submerge it in hot water for 5-10 minutes.
Shoutout to Cook's Illustrated for the science tip to roll the cookies in granulated sugar and then powdered sugar for maximum crinkles!