Add brown sugar to a large bowl

Add butter to skillet and melt on medium heat. Continue to stir as it begins to foam slightly. When you see light brown flecks begin to appear at the bottom of the butter, continue stirring and keep an eye on it. When the flecks turn golden brown remove the butter from the heat and continue to stir.

When the flecks are a deep brown, pour the butter into the bowl with the brown sugar. Immediately whisk to combine.

Let mixture cool for 5-10 mins. Meanwhile, mash the bananas

Once it is cool, whisk in eggs and vanilla extract

Add bananas into mixture, mix well

Add flour, baking soda and salt. Stir with spatula

Split batter into 2 bowls

Blend the sesame seeds into a sand-like texture in food processor and add them to one half of the batter and mix.

In a parchment-lined loaf pan, add about 1/4 of the banana batter to the bottom and spread it out thinly. Then add a layer of the black sesame batter and spread it out. Repeat this process until all the batter is used up.

Insert a long skewer into the bread and swirl to create a marble patter

Bake at 180C for 50-60mins