The perfect banana bread contains one special ingredient… buttermilk!
Prepare 9x5 loaf pan. (I used two smaller loaf pans.)
In a stand mixer on medium-high, cream butter and sugar together for about 2 minutes. Add eggs, one at a time with mixer on low speed. Add in buttermilk and vanilla until the batter is just combined.
Remove bowl from mixer and fold in mashed banana's.
Divide batter into greased and floured bread pans and bake at 350°F for 50-55 minutes or until a toothpick comes out mostly clean.