1/4 cup butter
3/4 cup brown sugar
1 1/2 cups white sugar
1 egg
1 teaspoon vanilla extract
2 1/2 cups all-purpose flour
1 teaspoon baking powder
1/4 teaspoon baking soda
1 teaspoon ground cinnamon
2 teaspoons pumpkin pie spice
1/4 teaspoon ground nutmeg
1/4 teaspoon salt
3 eggs
1 1/2 tablespoons vegetable oil
1/4 cup brown sugar
1/8 teaspoon vanilla extract
Preheat oven to 375 degrees F (190 degrees C). Grease and flour two 9-inch round pans.
In a large bowl, cream together the butter, brown sugar, white sugar and brown sugar until smooth. Beat in the egg and vanilla until well blended. Stir in the flour, baking powder, baking soda, cinnamon and pumpkin pie spice. Mix in the brown sugar mixture, then mix until there is a fudgey look. Divide the batter evenly between the two pans.
Bake 18 to 20 minutes in the preheated oven, until a toothpick inserted into the center of the cake comes out clean. Allow to cool.
In a large bowl, cream together the butter mixture and brown sugar; stir in the egg mixture and pumpkin pie spice. Beat in the brown sugar mixture alternately with the brown sugar/vanilla mixture. Spread frosting evenly over the cooled cake.