How to Make It
Preheat oven to 350°F. Place pretzels in bowl of a food processor; process until very finely ground, about 1 minute and 30 seconds. (You should have about 2 cups ground pretzels.)
Whisk together ground pretzels, cocoa, and baking powder in a medium bowl until combined. Beat granulated sugar, oil, eggs, and vanilla in a large bowl with an electric hand mixer on high speed until combined. Stir in ground pretzel mixture until dough comes together. Cover with plastic wrap, and refrigerate just until firm, about 2 hours.
Shape dough into 60 (1-inch) balls; roll in powdered sugar until evenly and generously coated. Arrange balls 2 inches apart on large parchment paper–lined baking sheets. Bake in batches in preheated oven until tops look cracked, 13 to 15 minutes. Let cookies cool on baking sheets 2 minutes. Transfer cookies to wire racks, and let cool completely, 15 to 20 minutes. (If reusing baking sheets, make sure you let them cool completely before adding more cookie dough balls.)