Totally stolen from Milli Taylor after seeing this on her instagram @millitaylor
Needs to be started 24h in advance so the raisins are well soaked…
100g sultanas or raisins
150ml dark rum
180g unsalted butter
2 medium eggs
2 large bananas very ripe, (blackening) well mashed
150g plain flour
100g muscovado sugar
40g Demerara sugar
3.5 tsp baking powder
Pinch of sea salt
80g nuts (optional, hazelnuts work well)
In a small pan bring the rum just to be boil and then add the dried fruit. Swirl around and leave to soak for at least 10h, ideally 24h.
Brown the butter now, by cutting into small pieces and heating in a little pan, swirl around to get it to mix well, let it foam. It is ready when it is a caramel colour. Should smell nutty but not go black. Leave to cool and if it need storing keep in the fridge overnight.
To make the cake…. Preheat oven to 175C fan.
Take a 2lb loaf tin (approx. 21cm l x 11cm w x 7cm h) and rub it well with soft butter. Then add the Demerara sugar and tap and tilt the tin around to coat the bottom and sides with the sugar. The tin has to be well buttered for this to work, the sugar will coat it all.
In a large bowl (use electric whisk, hand one is fine), beat the eggs and muscovado sugar until pale and thick (will take a few mins, by thick it means there should be ribbons in the batter when you lift the whisk out).
Then add the rum soaked fruit and any liquid, the mashed bananas, (cool) brown butter and mix with a spoon.
Now add flour, salt and the baking powder and finally the chopped nuts if using. Put the mix into the sugared tin and bake for approx. 50 mins. Check with a toothpick to see if done and do another 5 if still a little sticky. Leave to cool for 20 mins and then turn the cake out onto a rack. As it cools the sugar will go crunchy on the outside.