Preheat oven to 325°F. Spray loaf pan (about 9x5.5”) with cooking spray.
Mix oil, peanut butter, and sugar in a large bowl with a hand mixer until smooth.
Add the bananas, eggs, sour milk, and baking soda to a blender. Blend until liquid forms.
Add 1/2 of the liquid and 1 cup of flour, stir until just moistened, then add remaining banana mixture and 1 cup flour.
Stir just until combined.
Place batter in the prepared pan. Bake for 45-55 minutes, until the top has browned an a toothpick comes out of the center clean, but may have a few crumbs stuck to it. If the top starts getting too brown, you can cover it with foil during baking. Cool completely before removing from the pan.
Make the glaze: whisk melted butter and powdered sugar. Add extracts, whisk until smooth. Add heavy whipping cream, whisk until smooth. Immediately pour over the top of the bread and spread to the edges. Let dry before cutting.