Preheat oven to 325°F. Beat the butter and sugar until creamy and smooth. Beat in the salt and flour until large clumps form. Add orange peel, zest, juice, and vanilla.
Mix well and press the dough into a tight ball. Shape according to how you want your slices to come out (rectangles, squares, rounds, wedges), wrap in plastic wrap and refrigerate for a couple of hours.
Slice the dough to 1/4 inch thickness and place on cookie sheet with enough space between for spreading. Bake 25-30 minutes or until golden. Let cool completely on cooling racks.
Melt chocolate gently. Dip cooled cookies in chocolate or drizzle with chocolate and let cool until chocolate sets.