In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt until the cocoa is evenly blended and there are no streaks. Set aside.
2 1/4 cups all-purpose flour, 1/4 cup unsweetened cocoa powder, 1 1/2 teaspoons baking powder, 1/2 teaspoon fine sea salt
In a large mixing bowl, beat the softened butter, granulated sugar, and brown sugar together with a hand mixer or stand mixer fitted with the paddle attachment on medium speed for 2–3 minutes, until lighter in color and fluffy. Scrape down the bowl once or twice.
1/2 cup unsalted butter, 3/4 cup granulated sugar, 1/2 cup light brown sugar
Beat in the eggs one at a time on low speed, mixing just until combined after each addition. Add the vanilla extract and white vinegar, then add the red food coloring. Start the mixer on low so the color doesn’t splash, and beat until the mixture is evenly red, adding a few more drops of color if needed.
2 large eggs, 1 1/2 teaspoons pure vanilla extract, 1 teaspoon white vinegar, 1 1/2 tablespoons red liquid food coloring
Add the dry ingredients to the red mixture in two additions, mixing on low speed until just combined after each. The dough will be fairly thick and a bit sticky, like a soft brownie batter. Do not overmix; stop as soon as no dry flour remains.
2 1/4 cups all-purpose flour, 1/4 cup unsweetened cocoa powder, 1 1/2 teaspoons baking powder, 1/2 teaspoon fine sea salt
Cover the bowl tightly with plastic wrap or a reusable lid and chill the dough for at least 2 hours and up to 24 hours, until firm enough to roll. This helps the dough firm up, deepens the flavor, and improves the crinkle effect.
When ready to bake, preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats. Place 1/2 cup granulated sugar in one shallow bowl and the powdered sugar in another.
1/2 cup granulated sugar, 3/4 cup powdered sugar
Using a small cookie scoop (about 1 1/2 tablespoons of dough) or a spoon, scoop portions of chilled dough and roll each into a smooth ball with your hands. If the dough is too sticky, chill it longer or lightly dust your hands with powdered sugar.
Roll each dough ball first in the granulated sugar, coating it fully, then roll it in the powdered sugar, pressing gently so a thick, even layer adheres. The double coating helps the powdered sugar stay bright and defined.
1/2 cup granulated sugar, 3/4 cup powdered sugar
Place the coated dough balls on the prepared baking sheets, spacing them about 2 inches apart. Bake for 10–12 minutes, or until the tops are crackled and the edges look just set. The centers should still appear slightly soft for a chewy texture.
Let the cookies cool on the baking sheet for 5 minutes to finish setting, then transfer carefully to a wire rack to cool completely. If baking two trays at once, rotate the pans halfway through baking for even results.