Preheat oven to 375 degrees F (190 degrees C). Grease muffin cups or line with paper muffin liners.
In a large bowl, cream together shortening and 1 cup sugar; beat in egg. Stir together flour, baking powder, salt and 1/4 teaspoon cinnamon. Stir flour into egg mixture alternately with milk. Spoon batter into prepared muffin cups.
Bake in preheated oven for 20 minutes, or until a toothpick inserted into center of a muffin comes out clean. While muffins bake, combine 1/2 cup sugar and 1 teaspoon cinnamon. Remove muffins from pan and let cool for 5 minutes. While muffins are still warm, roll tops of muffins in cinnamon sugar mixture.