In small saucepan melt butter in milk, keep warm. Beat thoroughly 4 eggs and 2 cups sugar. Add flour and vanilla, beat. Add hot milk and melted butter; beat. Add baking powder, beat thoroughly.
Tube pan or 13 x 9 inch or two 9 inch rounds. Grease and flour pans. Bake at 350 degrees for 55-60 minutes or until toothpick comes out clean.