Sourdough Streusel Cake

Cake
1 cup sourdough starter
1 cup flour
1 egg
1/2 teaspoon baking soda
1/2 cup granulated sugar
1/4 cup vegetable oil
1 teaspoon vanilla extract
3/4 teaspoon cinnamon
1/4 teaspoon salt

Streusel
1/2 cup brown sugar, firmly packed
1/2 cup granulated sugar
1 heaping tablespoon flour
1/3 cup margarine

Cake: Mix sourdough, flour, egg, baking soda, sugars oil, vanilla extract, cinnamon and salt. Pour into greased pan.

Mix Streusel ingredients and sprinkle on top of batter. Nuts may be added, if desired.