Preheat oven to 350 degrees F. Butter and line a 9-by-5-inch loaf pan with parchment paper (cut a 9-inch wide strip of parchment and press it into the pan, covering the bottom and sides, leaving at least a 1-inch overhang on the long edges; it’s ok if the short ends are left unlined so long as they are buttered).

Peel and cut the banana in half, both length wise and cross wise: each banana should be in four half moons shapes.

Heat a heavy skillet over medium high heat and melt 1 1/2 tbsp butter.

Once the butter has melted and is starting to bubble, you can add the banana slices to the pan. Let them turn golden brown on all sides, just being careful not to let any one side scorch. As soon as they have caramelized, transfer to a bowl to cool down a bit.

In a large bowl, sift or whisk together flour, baking powder, baking soda, and salt and set aside.

Mash bananas in a bowl until mostly smooth (If you only have frozen bananas you can let them thaw and mash at this point). You should have about 3/4 cup.

Whisk in eggs, then add sugar, brown sugar, and vanilla and whisk to combine. Finally whisk in melted stick of butter.

Pour wet ingredients into bowl with dry ingredients and whisk until just incorporated and no streaks of dry ingredients remain. Transfer about half of batter to another bowl; mix in black sesame paste and ground sesame seeds until evenly incorporated. Then add in 6 good dashes of chocolate bitters and give it a good stir.

Using one large serving spoon and one of the batters, dollop a spoonful into the centre of the pan. Use a separate spoon for the alternate batter and dollop the same amount right on top. Give the pan a good shake back and forth to help them start spreading out.

Keep alternating batters, and shaking occasionally until you have used up all the batter.

As you get towards the end of the batters, spread them out so that the pan is filled somewhat evenly. There may still appear to be more settled in the middle. No worries, it will even out as it bakes.

Sprinkle with turbinado or raw sugar as well as the sesame seeds all over the top of the batter.

Bake for about 50 minutes or until a bamboo skewer inserted near the center comes out mostly clean with a few moist crumbs attached.

Place pan on a wire cooling rack and let cool.

To remove, run a thin metal spatula along the short (unlined) sides of the pan. Use the overhanging parchment to gently lift the entire loaf out of the pan and place on a cutting board to slice and serve. Store in an airtight container at room temperature for up to 3 days.