Step 1

Adjust the oven rack to the middle position, pre-heat the oven to 355ºF (180ºC) and line a 2lb/900g loaf baking tin with greaseproof/baking paper. (Dimensions of the loaf tin: 8inch/21cm long, 4inch/11cm wide and 3inch/7cm high.)

Step 2

Mix the mashed bananas with the lemon juice (to prevent oxidation and browning) and set aside.

Step 3

In a bowl, whisk together the melted butter and both sugars until pale and fluffy.

Step 4

Add the mashed bananas, eggs and vanilla paste, and whisk until well combined.

Step 5

Sift together the plain gluten free flour blend, almond flour, xanthan gum, baking powder, baking soda, salt, cinnamon and nutmeg, and add them to the wet ingredients. Whisk or stir well until you get a smooth batter with no flour clumps.

Step 6

Spoon out 1/3 of the batter and mix into it the melted cooled chocolate and Dutch processed cocoa powder, until well combined.

Step 7

Alternately spoon the two batters into the lined loaf tin until no batter remains (see post above for photos on how to do this). Then, use a skewer or knife to swirl the batter around the tin – make sure you reach all the way to the bottom of the tin. Don’t be shy about giving the batter a generous swirl, but also don’t over-swirl it, as it can destroy the effect of having two distinct batters.

Step 8

Bake in the pre-heated oven at 355 ºF (180 ºC) for about 60 minutes, or until well risen, golden brown on top and an inserted toothpick/skewer comes out clean or with a few stray crumbs attached. If the banana bread starts browning too quickly or too much, cover it with aluminium foil (shiny side up) and continue baking until done. It's best to cover it with aluminium foil when it starts becoming a deep golden colour.

Step 9

Once baked, allow it to cool in the tin for 5 - 10 minutes, then remove out of the tin and allow to cool completely on a wire cooling rack. (Although it's rather wonderful still slightly warm.)

Step 10

Storage: The gluten free marbled banana bread keeps well in a closed container in a cool dry place for 3 - 4 days.