1 c. flour
1 1/2 c. 10X sugar
12 egg whites
1 1/2 tsp. cream of tartar
1 c. sugar
4 beaten egg yolks
1 tsp. orange rind
1 tsp. vanilla

FROSTING:

1/2 c. butter
2 egg yolks
1 1/2 tsp. orange rind
3-4 c. 10X sugar
1 tsp. lemon juice
4-5 tbsp. orange juice

Sift together flour and 10X sugar; set aside. Beat egg whites and cream of tartar until frothy. Gradually add sugar. Beat until stiff. Sprinkle 10X flour mixture over whites and gently fold until flour disappears. Divide in half, to one half add vanilla. To other half add rind and yolks. Alternate in ungreased tube pan and gently marble. Bake at 375 degrees for 35 minutes. Invert until cool.

Frosting:

Cream butter. Add yolks and rind. Beat well. Add part of 10X sugar and lemon juice. Add rest of 10X sugar alternately with orange juice. Mix until spreadable.