Cream the butter and powdered sugar in a bowl. Add the flour and salt and mix well to combine.
Roll the dough out with a rolling pin. (The dough will be crumbly like pie dough. Work it together with your hands until it rolls out.)
Cut the dough into circular shapes and place on baking sheet.
Bake for 10-12 minutes. Remove from oven and cool.
For the ganache:
Heat a double boiler and add chocolate chips, heavy whipping cream, and instant coffee granules. Stir together until combined.
Dip one half of the cooled cookie into the ganache. Sprinkle sliced almonds over the chocolate half. Set aside to let the ganache set.
The chocolate may clump a bit when first melted. Slowly continue to add heavy whipping cream while the water is on a low boil and stir with a whisk for a few minutes and the ganache should become smooth.