Ingredients
Equipment
Method
Make the cookies
- Beat the butter and sugar in a large bowl with an electric mixer on medium speed until creamy, about 2 minutes.
- Beat in the egg yolk and vanilla until combined, then mix in the flour, cocoa powder, and salt just until a soft dough forms.
- Line two large baking sheets with parchment paper.
- Roll the dough into 24 balls about 1 inch wide, and place them 2 inches apart.
- Press a deep indentation into each ball with your thumb or the back of a teaspoon.
- Refrigerate the shaped cookies on the baking sheets for 30 minutes.
- Heat the oven to 350°F.
- Bake both sheets for 10–12 minutes, switching their rack positions and rotating them front to back halfway through, until the cookies look set.
- Gently press the indentations again if they have puffed up.
- Cool the cookies on the sheets for 10 minutes.
- Transfer the cookies to a rack to cool completely.
Make the peppermint filling
- Put the chopped chocolate in a heatproof bowl.
- Heat the cream in a small saucepan over medium heat until steaming and just beginning to simmer.
- Pour the cream over the chocolate and let stand for 3 minutes.
- Stir the chocolate mixture until smooth.
- Stir in the peppermint extract.
- Spoon the filling into the cooled cookie indentations.
- Sprinkle with crushed peppermint candy while the filling is still soft.
- Let the filling set at room temperature for about 1 hour before serving.
Notes
For neat indentations, press them again gently after baking if they puff up. Store in an airtight container in the refrigerator for up to 5 days; freeze yes, in a sealed container. For a dairy-free version, use dairy-free butter, cream, and semisweet chocolate.