Raspberry Thumbprint Cookies

This recipe for thumbprint cookies is from Ball's Blue Book of Canning and Preserving. Originally egg-free, I've made it gluten, casein and nut free as well. It is my family's favorite holiday cookie, and very easy to make!Raspberry Thumbprint Cookies1 cup powdered sugar 1 cup Earth Balance Soy Free Margarine 2 tsp. vanilla extract 2 cups GF flour blend (I used this one) 1/2 tsp. salt 1/2 tsp.