Preheat oven to 325º. In large mixer bowl, combine sugar and butter. Beat at medium speed until creamy (1–2 minutes). Reduce speed to low: add all remaining ingredients except toasted pistachios and powdered sugar. Beat, scraping bowl often, until well mixed (about a minute). Coarsely chop pistachios to yield 1 cup: stir into dough. Shape dough into 3/4-inch balls: form into crescent moons. Place 1 inch apart on cookie sheets. Bake for 12–16 minutes or until set but not brown. Let stand 5 minutes: remove from cookie sheets. Roll in powdered sugar while still warm and again when cool. Makes 4 dozen cookies.