Ingredients:
1 (18.25) package lemon cake mix
2 eggs
1/3 cup vegetable oil
2 teaspoons lemon zest
4 TBS fresh lemon juice
1/4 - 1/2 cup all purpose flour
Buttercream Frosting:
3 cups powdered sugar
3/4 cup butter, softened
zest of one lemon
1 teaspoon vanilla extract
2-3 tablespoons lemon juice
Directions:
Preheat oven to 375 degrees. Pour cake mix into a large bowl. Stir in eggs, oils, lemon juice, and lemon zest until blended. If mixture is very wet slowly add 1/4 to 1/2 cup of flour until the dough comes together.
Drop teaspoons of dough onto an ungreased cookie sheet. Bake 7-9 minutes in the preheated oven. The bottoms will be light brown. Move cookies to a cooling rack and using your spatula gently flatten your cookies.
Frosting:
Cream sugar, butter, lemon zest, and vanilla. Add 2 tablespoons of lemon juice and beat until fluffy, adding more if needed.
Assembly:
Frost the flat side of the cookie with a good dollop of frosting. Lightly place the flat side of an unfrosted cookie on top. Press down until a bit of the frosting begins to poke out of the sides. If you want to decorate the edges, place your sprinkles/chips/etc. in a small bowl, and dip the sides of the cookie in it, rolling the cookie around to coat all sides.
http://www.bakedperfection.com/2009/06/lemon-sandwich-cookies.html
