Instructions

1. Preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper.
2. In a medium bowl, whisk together the all-purpose flour, cocoa powder, and salt until well combined and no lumps remain.
3. In a separate large mixing bowl, cream the softened butter and granulated sugar together using an electric mixer until light and fluffy, about 3-4 minutes.
4. Add the egg yolk to the butter mixture and beat until fully incorporated. Pour in the Baileys Irish Cream and mix until smooth.
5. Gradually add the dry ingredients to the wet ingredients, mixing on low speed until a soft chocolate dough forms.
6. Chill the dough in the refrigerator for 15-20 minutes to make it easier to handle.
7. Roll the chilled dough into 1-inch balls and place them 2 inches apart on the prepared baking sheets.
8. Use your thumb or the back of a small spoon to create a deep indentation in the center of each cookie.
9. Bake the cookies for 12-15 minutes, until the edges are set but the centers are still slightly soft.
10. Remove from the oven and immediately reinforce the thumbprint indentation if needed while cookies are still warm.
11. Allow cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
12. Once cooled, fill the centers of the cookies with chocolate ganache or your preferred jam.
13. Let the filling set for 10-15 minutes before serving or storing in an airtight container.