1. Preheat oven to 350 degrees F. 2. Prepare desired pan (s)-two 8" layer pans or a 13 x 9 x 2" sheet pan or an 8" ring pan by buttering well and dusting lightly with flour. 3. Cream butter and sugar. 4. Beat in egg yolks thoroughly. 5. Add vanilla. 6. Sift together flour, baking soda, and salt in a small bowl. 7. Alternately add dry ingredients and sour cream to the butter mixture, mixing well after each addition. 8. Keep mixing until very smooth. 9. Stir in poppy seeds until evenly distributed. 10. By hand, using a spatula, fold in stiffly beaten egg whites, carefully incorporating them into the batter. 11. Pour into prepared pan (s). 12. Bake at 350 degrees for 25-30 minutes for layers, 35-40 minutes for sheet, 50-55 minutes for ring. 13. Watch carefully. 14. Cake should pull from sides of pan, and a toothpick should come out clean from the center. 15. Cool for 5 minutes in pan, then turn and release onto rack, cooling completely before finishing. 16. For Icing: Soften butter and cream cheese at room temperature for a few hours. 17. Beat cream cheese and butter together with an electric mixer until they are completely incorporated and the mixture is very light and creamy. 18. Mix in sifted powdered sugar, 1 cup at a time, beating well after each addition. 19. Chill icing in a bowl covered with plastic wrap for about 1 hour before spreading. ---------------------------------------------------------------------------
Nutrition
Ingredients
