Preheat the oven to 300°F (150°C).
In a medium mixing bowl, cream together the butter, sugar, and salt until sugar is well mixed in.
Add the flour and ground espresso beans and mix until the dough holds together. If necessary, use your hands to gently knead the dough together into a ball.
On a lightly floured surface, roll the dough out to 1/4-in (6 mm) thick. Cut out cookies using a 1 1/2- to 2-in (4- to 5-cm) star cutter. You can reroll scraps and cut out more stars, but take care not to overwork the dough. This cookie will be delicious in many different sizes and shapes. Use what you prefer and what you’re able to find. If you choose a much bigger cutter, leave them a little thicker. If they are large and too thin they will break easily.
Carefully place cut cookies on a baking sheet lined with parchment paper, evenly spaced about 1 in apart.
Bake for 30 minutes. The tops should look dry and cookies should be slightly browned. Cool on the baking sheets for 5 minutes, then transfer to a rack to cool completely to room temperature before dipping in melted chocolate.