1/2 cup shortening
1/4 cup white sugar
1 egg
1 1/2 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon ground cinnamon
1 teaspoon salt
1 teaspoon vanilla extract
1 cup milk
1 1/4 cups whole wheat flour
1 1/2 cups packed brown sugar
1 teaspoon ground cinnamon
3/4 cup rolled oats
Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x13 inch baking dish.
In a large bowl, cream together shortening and white sugar until smooth. Beat in egg, 2 cups flour and baking powder. Stir in the flour mixture, followed by brown sugar; beat again. Stir in the cinnamon and salt. Fold in the vanilla. Spread the batter into the prepared dish.
Place the top of the peach muffin over the batter. Bake in preheated oven for 25 to 35 minutes, or until muffins are golden brown. Remove muffins from oven.
While muffins are in oven, melt oats with the brown sugar, stirring every few minutes. Spread not too much oat mixture over the muffin, but not all. Place the brown sugar back in the oven to melt. Spread over muffins, allowing the muffins to hang out on the sides of the pan.
Bake in preheated oven for 30 minutes, or until a toothpick inserted into the center of a muffin comes out clean.