Created by KittenCal on November 22, 2011
Step 1: Preheat oven to 350 degrees F. Set oven rack to second-lowest position. Butter a 13 x 9-inch baking pan.
Step 2: In a bowl sift both flours with baking soda and salt; set aside.
Step 3: In another small bowl mix the buttermilk with the mashed banana; set aside. Cream the butter with oil, both sugars and vanilla together until fluffy (about 3-4 minutes).
Step 4: Add in the eggs one at a time to the creamed mixture beating well after each addition. Add in the banana/buttermilk mixture; beat until combined. Mix in the poppy seeds.
Step 5: Add in the flour mixture to the creamed mixture with a wooden spoon just until combined (do not over mix).
Step 6: Transfer batter to prepared baking pan. Bake for about 30-35 minutes, or until cake test done. Frost with favorite cream cheese frosting or dust with powdered sugar.