Preheat oven to 400 degrees. In a large bowl, sift together flour, baking soda, and cream of tartar. Add softened butter and sugar, mix well. Stir in milk or buttermilk. Also stir in raisins or dried fruit. Press dough onto a floured surface and roll out gently to 1/2-inch thickness. Cut scones into round shapes or triangles. Brush scones with egg wash for shine. Bake for 20 minutes or until golden brown.