These are from Rose Levy Berenbaum's "Christmas Cookies, " and are quite good. Preheat oven to 350 degrees. Soften butter. Mix flour, baking powder and soda, salt, and cashews. Cream butter and sugar; beat in eggs and vanilla. Mix in sour cream. Add flour mixture. Drop dough by teaspoons onto greased cookie sheets. Bake 10-15 minutes until golden brown. Makes roughly 6 dozen.