Preheat oven to 350, Grease a 10 inch tube pan. Cream together margarine and both sugars until light and fluffy.Cream in eggs, one at a time til each is well blended in. Mix in Vanilla and buttermilk until well blended.
Sift together four,baking powder,baking soda ,salt and spices. Mix dry ingredients into creamed mixture.Gently stir in Vidalia onion puree and then (pecans are optional) until well blended.
Pour into tube pan . Bake for 45 minutes.Let the cake cook for 20 minutes and then remove from pan.
you can ice if you would like ..but I prefer no icing on mine !! Enjoy