Preheat oven to 400 degrees. In a large bowl, cream butter and 1/2 cup powdered sugar until smooth. Add almond and vanilla extracts. Slowly add flour and salt to butter mixture, and mix until incorporated. Mix in pecans and walnuts.

Use a cookie scooper to scoop the dough and then roll into balls (or use your hands to form 1" balls). Bake for 10-12 minutes. (These cookies barely brown, so if they don't look done, it's okay!).

Roll in powdered sugar while still warm, and roll again when cool.