Preheat oven to 350 degrees Fahrenheit. Grease and flour an 8" or 9" cake pan.
Combine the topping ingredients (1-1/2 Tablespoons sugar and 1/2 teaspoon cinnamon) in a small bowl. Set aside and reserve for sprinkling on top of batter.
Combine the dry ingredients for the cake in a bowl.
In a separate large mixing bowl, beat together egg, shortening and vanilla. Gradually beat in dry ingredients; then beat in sour cream or sour milk.
Pour into prepared cake pan. Sprinkle the sugar/cinnamon mixture evenly over top of batter.
Bake at 350 degrees Fahrenheit for 40 to 45 minutes.