Cream butter, sugar and cream cheese preferably in a stand-mixer. Add egg yolks, one at a time, beating after each addition. Add flour, soda, and vanilla and mix well. Fold in beaten egg whites. Pour into well-greased bundt pan. Bake in a pre-heated 300 degree oven for 1 1/2 hours or until done. Cool on wire rack. Slice and serve with fresh strawberries (or peaches)and whipped cream.