Vanilla Sandwich Cookies

3/4 gfcf margarine
2 cups flour (I used Hagman's 4 flour bean mix, or mix brown rice w/garfava 3:1)
3/4 cup sugar
2 tsp. xanthan gum
2 eggs
1/4 tsp. baking soda
2 tsp gf vanilla extract
1/4 tsp. baking powder
1/4 tsp. salt

Preheat oven to 350 degrees F. Cream margarine and sugar. Beat in eggs & vanilla, blending until smooth. Combine dry ingredients, then add to wet. Wrap dough in plastic and chill until firm enough to roll. Roll out on gf floured surface. Cut out cookies and bake on greased sheets 12 minutes or till just golden at edges. Cookies are soft but will firm up a bit as they cool. Filling: 1/2 cup gfcf margarine 1 1/2 cups powdered sugar. 1 Tbsp gf vanilla extract. Blend the margarine and sugar until smooth (using an electric mixer if possible). Blend in vanilla. The filling should be slightly firm but still spreadable. Use on half the cookies and top with the other half.