Allow egg whites and yolks to stand at room temperature for 30 minutes. Meanwhile, in a large mixing bowl combine the flour, sugar, baking powder, and salt. Make a well in the center of the flour mixture. Add oil, egg yolks, and pineapple juice in that order. Beat with an electric mixer on low speed until combined. Beat on high speed for 5 minutes more or until batter is satin smooth.

Thoroughly wash the beaters. In a very large mixing bowl beat egg whites and cream of tartar with an electric mixer on medium speed until stiff peaks form (tips stand straight). Pour batter in a thin stream over beaten egg whites; fold in gently. Pour into an ungreased 10-inch tube pan. Set pan on a baking sheet or pizza pan.

Bake in a 325 degrees F oven for 60 to 70 minutes or until top springs back when lightly touched. Immediately invert cake (in the pan); cool thoroughly. Loosen sides of cake from pan; remove cake.

Frost cooled cake with Pineapple-Buttercream Icing. If desired, decorate with Pineapple Daisies. Makes 12 servings

Pineapple-Buttercream Icing: In a large mixing bowl beat 1/2 cup softened butter with an electric mixer on medium speed for 30 seconds. Gradually add 2 cups sifted powdered sugar, beating well. Stir in 6 tablespoons well-drained crushed pineapple and 2 tablespoons pineapple juice. Beat thoroughly. Gradually beat in 2 1/2 to 2 3/4 cups sifted powdered sugar until of spreading consistency. Spread on top and sides of cake.

Pineapple Daisies: Cut pineapple slices into thin wedges for daisy petals and use a maraschino or candied red cherry for flower centers and fresh mint for leaves.