Cream butter and sugar until light and fluffy. Add vanilla. Sift together flour, salt, and baking powder. Stir dry ingredients into butter mixture; mixing until well blended. Shape dough into small balls. Place on ungreased cookie sheets; press an almond half into the top of each ball. Bake butter cookies at 300° for 20 minutes, or until just lightly browned. Makes 5 to 6 dozen butter cookies.
