buttermilk banana bread

I like my banana bread straight-up. No nuts. No chocolate. Nothing. 
Slathering each slice with creamy butter is a must though.
1 1/2 C flour
3/4 tsp baking soda
3/4 tsp baking powder
1/4 C salted butter, room temperature
3/4 C sugar
1/4 C brown sugar
1 egg
1/2 C buttermilk
2-3 ripe bananas, mashed
1/2 tsp vanilla

1. Sift flour, baking soda and baking powder together in a bowl. 

2. Cream butter and sugars until smooth. Add the egg and mix until incorporated. Mix in the bananas.

3. Fold in the buttermilk and flour, alternating between the two and ending with buttermilk. Do not over mix.

4. Pour into a loaf pan lined with parchment paper. Bake at 325 degrees for about an hour or until a toothpick inserted into the centre comes out clean.