Grease springform pan, or 9×9″ square pan.
Sift flour, baking powder, baking soda and salt together.
Put eggs, butter or margarine, sugar and vanilla into blender (or mixer) and process until smooth. To this, gradually add half the sour cream and half the flour mixture; process until smooth. Repeat with remaining sour cream and flour.
Pour HALF the batter into prepared pan; Top with HALF the topping, spreading as evenly as possible.
Repeat with remaining batter and end with the last half of the topping.
Bake at 350°F. 45-50 minutes or until tester/toothpick comes out clean, trying not to over bake it so it won’t be dry.
Cool 10 minutes before removing from pan.
This cake freezes well!