Preheat oven to 375 degrees F. In a large bowl, beat butter with an electric mixer on medium to high speed for 30 seconds. Add granulated sugar and baking powder. Beat until combined, scraping bowl occasionally. Beat in ginger, orange peel, egg, orange juice, and vanilla until combined. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour.

Place unchilled dough in a cookie press fitted with a flower-shape plate. Press dough shapes 2 inches apart onto an ungreased cookie sheet. Bake in the preheated oven for 8 to 10 minutes or until edges are firm but not brown. Carefully cut each cookie in half with a sharp knife. Transfer cookies to a wire rack; let cool.

Spread flat sides of half the cookies with some of the Orange Frosting. Top with remaining cookies, flat sides down. Place remaining frosting in a pastry bag fitted with a writing tip. Decoratively pipe frosting on filled cookies. If desired, sprinkle with pistachio nuts. Makes about 80 sandwich cookies.

In a large bowl, combine 4-1/2 cups powdered sugar, 3 tablespoons softened butter, and 1 teaspoon vanilla. Stir in 3 to 5 tablespoons orange juice, 1 tablespoon at a time, to make a frosting of piping consistency. If desired, tint frosting with orange food coloring. Makes about 1-1/2 cups.

Layer cookies, with or without frosting, between sheets of waxed paper in an airtight container; cover. Store at room temperature for up to 3 days or freeze for up to 3 months.