Preheat oven to 350F. Butter and flour a 9 x 5 inch pan.
Mash your bananas in a small bowl. If they aren't ripe enough bake on a sheet at 350f for about 10 minutes or until blackened.
Sift dry ingredients into a medium sized bowl. Set aside.
Cream butter, coconut oil and sugar together in stand mixer until light and fluffy.
Add the vanilla then the eggs one at a time. Let each egg incorporate before adding the next.
Mix in mashed bananas. Mix until fully incorporated.
Add the sifted dry ingredients and beat until combined.
Pour into the prepared pan. Level batter out a bit with a spatula.
Cut a banana into two thin lengthwise slices. Place on top of loaf toward the edges. Sprinkle with brown sugar.
Bake for 50-60 minutes or until a toothpick inserted into the center comes out clean.
Video
Notes
If your bananas aren't ripe enough just bake (in the peel) them at 350F (177C) for about 10 minutes or until they blacken.
To get those banana slices on the top cut thin slices and lay them on the top toward the edges. If they're in the center your slices will SINK!
For added depth of flavor you can try using 1/2 cup of browned butter for the fat. Just cook the butter on low heat in a pot stirring occasionally. Let is come to room temp and solidify overnight and cream with the sugar.
Don't worry if your mushed bananas have lumps. You will love the texture and pop of taste. You can add an extra half banana lightly mashed for an even more moist, slightly denser bread.