Cream butter and sugar together. Add eggs one at a time to the mixture and mix well. Add vanilla and mix well.Alternately add flour and sour cream a little at a time while mixing until all has been added. Beat a little longer until fluffy (about 5 minutes).
Pour into a well greased Bundt pan or angel food cake pan.
Bake at 300 degrees for 1-1/2 hours or until a straw comes out clean.
Notes
Tip: I use my Kitchen Aid mixer when I make these cakes because it's easier to let it mix while I add each egg one at a time and add the sour cream and flour.