1.   Combine buttermilk and soda and add to creamed mixture alternately with flour, beating well after each addition.

2.   Combine flour, soda, salt and cream of tartar in medium mixing bowl and add to creamed mixture, beating well.

3.   Sift the flours together in another bowl and fold quickly and gently into the creamed mixture in three batches.

4.   Alternately add to the creamed mixture with the buttermilk, ending with the milk.

5.   At low speed, gradually add to creamed mixture until well blended.

6.   Blend into creamed mixture.

7.   Add flour mixture and sour cream alternately to creamed mixture, beating well after each addition.

8.   Add the flour mixture to the creamed mixture in three equal portions, alternating with poppy seed-milk mixture.

9.   Add to creamed mixture alternately with milk, beating well after each addition.

10.   Add dry ingredients to creamed mixture alternately with buttermilk.