1. Preheat oven to 350 °F (175 °C). Grease and flour a 9 inch round pan. Sift together the flour, baking powder, baking soda and salt. Set aside.
2. In a large bowl, cream together with the shortening and 1 cup sugar until light and fluffy. Beat in the eggs one at a time. Beat in the flour mixture alternatively with the sour cream, mixing just until incorporated. Put half of the batter into prepared pan. Mix together 1/4 cup sugar and 1 teaspoon cinnamon. Sprinkle half of mixture over batter in the pan. Cover with remaining batter, then top with remaining cinnamon sugar.
3. Bake in the preheated oven for 35 to 45 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.