Preheat oven to 350*. Cream sugar and butter. Add eggs and mix. Sift together flour, baking powder, baking soda and salt. ( I don't sift anymore, just whisk together before I add to wet ingredients). Add dry ingredients to creamed mixture, mix thoroughly. Add sour cream.
Make filling mixture by combining brown sugar, cinnamon and nuts if using. Put 1/2 batter in greased tube pan. Top batter with 1/2 filling. Spoon remaining batter over filling. Top with remaining filling. Bake at 350* for 45-50 mins.