In a mixer bowl, beat butter, sugar, almond extract, and salt until smooth. With mixer on low speed, add flour and orange zest; mix just until a dough forms. Add almonds and mix gently till nuts are incorporated throughout dough.
On a clean surface, form dough into a rectangular log, 12 inches long, 2 1/2 inches wide, and 1 inch thick. Wrap log in wax or parchment paper, and freeze until firm, at least 1 hour and up to 3 months. If freezing longer than 1 day, wrap log again, in plastic wrap.
Preheat oven to 300 degrees. Remove dough from freezer. (If dough has been in freezer a long time and is frozen solid, let it sit at room temperature 30 minutes so it slices without crumbling.)
With a sharp knife, cut dough into 1/4-inch-thick slices; place on ungreased baking sheet at least 1 inch apart. Bake until edges just begin to turn golden, 20 to 25 minutes. Cool 5 minutes on baking sheet; transfer cookies to a rack to cool completely.
Notes
-I keep this in the refrigerator, not freezer if I am going to bake within a couple of weeks.
-You can use any type of citrus zest: lime, lemon, orange in this cookie.
-Dipped in chocolate...yes.