Cream butter; gradually add sugar, beating until light and fluffy. Add egg yolks; beat well.
Combine flour, cream of tartar, soda, and salt; add to creamed mixture alternately with milk, beginning and ending with flour mixture. Mix well after each addition.
Beat egg whites (at room temperature) until stiff peaks form; fold into batter. Spoon into a greased 6-cup bundt pan. Bake at 400° for 25 minutes or until golden brown. Cool 10 minutes. Remove from pan; cool on wire rack.
Oxmoor House Homestyle Recipes