Lime Sandwich Cookies

Directions

1. 1
   In a big bowl, beat butter with an electric mixer on medium to high speed for 30 seconds.
2. 2
   Add in sugar and baking powder; beat until combined.
3. 3
   Beat in egg and lime juice until combined.
4. 4
   Beat in as much of the flour as you can with the mixer; stir in any remaining flour and the lime peel with a wooden spoon.
5. 5
   Knead in enough green food coloring for desired color.
6. 6
   Shape dough into two 8-inch long rolls; wrap in clear plastic wrap or waxed paper.
7. 7
   Chill 4-24 hours or until firm enough to slice.
8. 8
   Cut rolls into1/8-inch slices; place slices 1-inch apart on an ungreased cookie sheet.
9. 9
   Bake in a preheated 375° oven for 7-8 minutes or until bottoms are lightly browned.
10. 10
    Transfer cookies to a wire rack and let cool.
11. 11
    Spread bottoms of half the cookies with about 1 tablespoon of Lime-Pistachio filling; top with remaining cookies, flat sides down.
12. 12
    To make Lime-Pistachio Filling: in a medium-size bowl, beat butter with an electric mixer on medium to high speed for 30 seconds.
13. 13
    Gradually beat in 1 1/3 cup sifted powdered sugar; beat in lime juice until smooth.
14. 14
    Gradually beat in enough sifted powdered sugar (1 1/3 to 2 cups) to make of spreading consistency; stir in pistachio nuts.