TESTED & PERFECTED SOURDOUGH COFFEE CAKE Recipe. Step-by-Step. is perfect for busy families. Comes together quickly with a few staple ingredients! INGREDIENTSCAKE 1 cup sourdough starter 1?3 cup vegetable oil 1 egg (slightly beaten) 1 cup all-purpose flour 3?4 cup sugar 1?2 teaspoon salt 1 teaspoon baking soda...