1 cup white sugar
1/2 cup all-purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1 cup buttermilk
1 teaspoon baking powder
1 cup pumpkin puree
1 cup chopped pecans
3 teaspoons pumpkin pie spice
Preheat oven to 350 degrees F (175 degrees C). Grease and flour one 9 inch springform pan.
Sift together the flour, baking powder, baking soda, and baking powder; set aside.
In a large bowl, cream together sugar and margarine. Beat in pumpkin puree, 1 cup at a time, mixing just until incorporated. Beat in the pumpkin mixture until smooth.
Pour batter into prepared pan.
Bake in preheated oven for 35 minutes, or until a toothpick inserted into center of the cake comes out clean. Allow to cool completely before frosting.