4. Add the pistachios and beat on low speed until evenly distributed and the mixture turns green, 1 to 2 minutes. Add 1 cup rolled oats and beat until just combined, about 1 minute.

5. Turn off the mixer. Stir by hand to mix in any unincorporated ingredients. Cover the dough and refrigerate for 30 minutes. (The dough will be sticky at first, but the oats will absorb excess moisture.)

6. Arrange 2 racks to divide the oven into thirds and heat the oven to 350 F. Line 2 baking sheets with parchment paper or silicone baking mats. Place 1 cup powdered sugar in a small bowl.

7. Scoop out the dough with a 1 1/2-inch wide cookie scoop or in 2 rounded tablespoons portions. Roll each portion of dough in powdered sugar, coating generously and evenly. Place at least 1-inch apart on the prepared baking sheets, 12 per baking sheet.

8. Bake for 8 minutes. Rotate baking sheets between racks. Bake until the edges are dry and the powdered sugar on top starts to crack, 7 to 8 minutes more. Let cool slightly on the baking sheets for 1 to 2 minutes. (Do not let the cookies cool completely or they will not flatten.)

9. Using the bottom of a 1-cup measuring cup, press gently and evenly down on one of the cookies to flatten to about 1/2-inch thick. Carefully remove the measuring cup and wipe the bottom of the cup with a damp paper towel. Repeat until all the cookies are smashed. Let cool for 30 minutes. The cookies will stick to the parchment paper when warm but will release when cooled using a wide, flat spatula.

Recipe notes: The dough can be made up to a day ahead and refrigerated. Store cookies in an airtight container at room temperature for up to four days.

(Justin Burke is a contributor to TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to editorial@thekitchn.com.)

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