In the bowl of an electric mixer fitted with the paddle attachment, cream together the butter with the icing sugar, ground almond, and ground coffee.
Add the yolk and beat it in, then mix in the flour on low. Add 1 tablespoon of milk and mix so that the dough comes together.
Gather the dough into a ball and flatten into a disk. Wrap it in plastic wrap and chill for 1 hour.
Roll the dough out to at least an 11 inch disk. Fit the dough into a 9-inch tart pan with a removable bottom (I used Wilton pans you can find on Amazon). Make sure that the dough fits well into all the corners and the fluted edge. Use your rolling pin to trim the excess of dough, which you can gather into a disk and chill, then reroll and cut out cookie stars, which you can bake on a cookie sheet until golden brown to garnish the tart later.
Place the pan on a baking sheet and chill the unbaked pastry shell for about 1 hour til it is very cold and hard.
Meanwhile preheat the oven to 350ºF. When the pastry is very cold, remove the baking sheet with the tart from the fridge. Using a fork, poke holes all over the crust.
Bake the tart shell on the middle rack of the oven for 20 to 30 minutes, until the edges are golden brown and have pulled away from the sides just a little. As the tart shell bakes, check on it every 5 to 10 minutes to make sure there aren't any air pockets forming. If you see a lump of air, just poke it with a tooth pick, a fork, or a wooden skewer to release the air. Press the pastry gently to smooth it out.
When the tart shell is completely baked, remove the sheet pan from the oven. Allow to cool at least 15 minutes before unmolding. Check out my trick for unmolding a tart for this step. Allow to cool completely. Place the unmolded baked tart shell on a serving plate.