Chocolate Peppermint Thumbprint Cookies

Ingredients
* 2 cups all-purpose flour (spooned and leveled)
* 2/3 cup unsweetened cocoa powder
* 1/4 teaspoon fine salt
* 1 cup(2 sticks) unsalted butter, room temperature
* 1 cup granulated sugar
* 1 large egg
* 1 tablespoon pure vanilla extract
* 1/2 cup granulated or sanding sugar
* 1 cup semisweet chocolate chips
* 1/4 cup butter
* 1/2 - 3/4 teaspoon pure peppermint extract

Directions
1. Preheat oven to 350 degrees F, with racks in upper and lower thirds.
2. In a medium bowl, whisk together flour, cocoa powder, and salt.
3. In a large bowl, using an electric mixer, beat 1 cup each butter and sugar on medium-high until light and fluffy, 3 minutes.
4. Add egg and vanilla; beat to combine. With mixer on low, gradually add flour mixture and beat to combine.
5. Place 1/2 cup sugar in a small bowl. Roll dough into 1-inch balls, then roll in sugar to coat. Place balls, 1 inch apart, on two parchment-lined baking sheets. Bake 5 minutes.
6. Remove sheets from oven; with the bottom of a small round measuring spoon, make an indentation in center of each cookie.
7. Bake until cookies are just set but still look moist, 3 minutes (do not over-bake). Let cool on the cookie sheets on wire racks.
8. In a microwave-safe bowl, microwave chocolate chips and 1/4 cup butter in 20 second increments until melted, on 70% power. Once fully melted stir in the peppermint extract.
9. Let cool until thick enough to pipe, 5 minutes. Transfer mixture to a large zip-top bag or piping bag; snip 1/4-inch hole in one corner. Pipe chocolate into cookie indentations.
10. Store in airtight containers, up to 1 week.

Notes
I used sanding sugar when we rolled the cookies, which gave them a really nice sparkle!