- 1 cup all-purpose flour
- 1/2 cup confectioners sugar
- 1/4 cup unsweetened Dutch-process cocoa powder
- 1/4 teaspoon salt
- 1/2 cup (1 stick) cold unsalted butter, cut into small pieces
- 1 teaspoon pure vanilla extract
- 1 large egg yolk
- 3 ounces milk chocolate, coarsely chopped and melted
- In the bowl of a food processor fitted with a blade attachment, combie flour, sugar, cocoa powder, and salt. Add butter, vanilla, and egg yolk and process until mixture comes together into a moist ball. Scrape the dough onto a piece of plastic wrap and refrigerate for 30 minutes.
- Place a rack in the center and upper third of the oven and preheat the oven to 325 degrees F. Line two baking sheets with parchment paper. Set aside.
- Roll out dough between two sheets of parchment paper. Lightly flouring the bottom piece of partchment paper. Roll to 1/4 inch thick. Use a 2 1/2-inch round or heart-shaped cookie cutter to cut out dough and use a thin spatula to transfer cookies to the prepared baking pan.
- Bake cookies until firm to the touch, 20 to 25 minutes. Let cookies cool completely on wire racks.
- Melt milk chocolate in a small bowl in the microwave, heating for 30 second intervals, removing the bowl to stir the chocolate and repeat until the chocolate is completely melted.
- Allow the cookies to cool on a wire rack before dipping in chocolate. Sprinkle with sea salt or sprinkles and allow to rest for 30 minutes to harden the chocolate. Stir in an airtight container in the refrigerator for several days.