- 1. Preheat oven to 375 degrees F (190 degrees C). Grease a 9 x 5 inch loaf pan. 2. Cream butter or margarine and sugar till light and fluffy. Add eggs and beat well. Mix together flour and baking soda; blend into creamed mixture. Fold in buttermilk, vanilla, mango puree, and chopped nuts. Pour batter into prepared pan. 3. Bake for 40 to 50 minutes, or until done.