Combine butter and powdered sugar in a large bowl or the bowl of a stand mixer. Whisk with a hand mixer or stand mixer until smooth.
Add espresso powder, vanilla extract, and salt. Whisk until smooth.
Lastly, add all purpose flour and gently fold it into the mixture until it just comes together into a soft dough.
On a floured silicon mat, roll the dough out until it is 1/4 inch thick. Let it rest in the fridge for 30 minutes.
Prepare 2 baking sheets by covering them with parchment paper.
After 30 minutes, take the dough out from the fridge. Use a cookie cutter that is 2.5 inches in diameter to cut out your cookies. After you cut out your first batch, combine the remaining dough, and roll it out to cut more cookies. Repeat this process until you run out of dough.
Preheat the oven to 350 degrees F (177 degrees C).
While the oven is preheating place the cookies in the fridge to cool. The colder your cookies are, the less they will spread.
Bake cookies for 13-15 minutes until the edges start to brown.
Cool cookies for 10 minutes on the baking sheet and then transfer to a cooling rack to cool completely (~5 minutes).
Combine the dark chocolate and coconut oil in a small bowl. Heat in the microwave in 20 second increments until the chocolate melts. Mix the chocolate and coconut oil together until a smooth chocolate dip forms.
Dip half the cookie into the chocolate. Repeat this process for all the cookies.
Let the chocolate set for 10 minutes before serving. Or you can enjoy them right away!