We started our slice-and-bake mocha-peppermint cookie dough with melted rather than softened butter. This allowed us to skip the usual creaming step and simply stir in the sugar along with an egg yolk and peppermint extract.
A little baking powder opened up tiny air pockets in the dough and kept it from being too dense. The yolk’s proteins and the sugar gave the cookies a pleasantly firm and crumbly texture and extended their shelf life to 10 days, making them ideal for shipping or gifting.
Mocha-Peppermint Mosaic Slice-and-Bake Butter Cookies
Makes about 40 cookies- 1 3/4 cups all-purpose flour
- 1/2 teaspoon table salt
- 1/2 teaspoon baking powder
- 16 tablespoons unsalted butter, melted and cooled
- 3/4 cup granulated sugar
- 1 large egg yolk
- 1 teaspoon peppermint extract
- 1 1/2 tablespoons instant espresso powder
- 1 tablespoon unsweetened cocoa powder
- 1 tablespoon powdered sugar
- 1 tablespoon dry milk powder
2. Shape dough into a rough 8-by-5-inch rectangle. Wrap tightly in plastic wrap and refrigerate until firm, at least one hour or up to three days.
3. Sift espresso powder, cocoa, powdered sugar, and milk powder through a fine-mesh strainer into a medium bowl. Cut chilled dough into rough 3/4-inch pieces. Add to espresso-cocoa mixture and toss until pieces are evenly coated. Transfer pieces to counter, shaking excess espresso-cocoa mixture back into bowl (do not discard). Divide dough pieces into two piles.
4. Working with one pile, firmly squeeze one-quarter of pieces together to form dough ball with streaks of espresso mixture throughout (do not knead dough). Repeat with remaining three-quarters of dough to form three more balls. Squeeze and press dough balls together to form a rough 8-inch log. Continue to shape and roll log until 1 1/2 inches in diameter and about 9 inches long. Flatten log slightly on two sides, until it is 1 inch tall and has an oval shape. Repeat with remaining dough pile to form a second log.
5. Transfer reserved espresso-cocoa mixture to counter and roll logs in mixture to coat evenly. Wrap logs tightly in plastic and refrigerate until firm, about 30 minutes.
6. Adjust oven rack to middle position and heat oven to 350 degrees F. Line two rimmed baking sheets with parchment paper.
7. Slice logs into 1/4-inch-thick ovals and space 1 inch apart on prepared sheets. Let rest at room temperature for 10 minutes. Bake cookies, one sheet at a time, until puffed and tops look dry but centers are still very soft, 10 to 12 minutes, rotating sheet halfway through baking.
8. Let cookies cool on sheet for 10 minutes, then transfer to a wire rack and let cool completely, about 30 minutes. Serve. (Cookies can be stored at room temperature for up to 10 days.)