In a large mixing bowl, using mixer, beat butter, sugar, amaretto and salt until smooth and creamy.
With mixer on low, add the flour and mix until the dough forms.
Using a rubber spatula, mix in the almonds.
Form dough into a large rectangular log or 2 smaller ones. Wrap each log in plastic wrap and freeze for 30 minutes or refrigerate for 1 hour.
Preheat the oven to 325º. Using a sharp knife, cut the dough into 1/4 inch thick slices.
Place slices onto un-greased baking sheets spaced 1 inch apart.
Bake until the edges are golden brown, about 12 minutes.
Cool for 10 minutes, then transfer to a wire rack to cool completely.