Combine sugar, baking soda, baking powder, flour and salt in a large bowl. Stir in eggs and sour cream, then add raisins and caraway seeds. Mix together and then add eggs, buttermilk, and sour cream. Pour into two greased and lightly floured loaf pans or round pans.
Bake at 325 degrees F for 60 minutes, or until a toothpick inserted in the bread comes out clean.