1 pkg. yellow cake mix
4 eggs
1/2 c. water
1 sm. pkg. pistachio pudding
1 c. sour cream

Mix and beat 2 minutes at medium speed all ingredients. Pour into greased and floured bundt or tube cake pan. Bake at 350 degrees for 40 minutes. Cool in pan for 10 minutes. Remove from pan and sprinkle with powdered sugar if desired.