Often a ‘rum and raisin’ recipe will ask for rum essence but it’s nowhere near as good as the real thing that we use here and, because of that, these biscuits have a bit more of a kick. There is a warning in the recipe which says not to overwork the buttercream, so take heed because – if you walk away and leave it to its own devices – you will come back to a scrambled mess.
For the biscuits
220g self-raising flour
1 tbsp bicarbonate of soda
80g light muscovado sugar
pinch of sea salt
150g unsalted butter, softened
100g golden syrup
For the filling
100g unsalted butter, softened
50ml dark rum
100g icing sugar, sifted
Preheat the oven to 140°C/fan 120°C/gas mark 1.
For the biscuits, combine the flour, bicarbonate of soda, sugar, raisins and salt in a large mixing bowl (or use a food mixer fitted with the beater attachment), then mix in the butter and golden syrup until thoroughly combined.
Divide into 16 balls (about 1 heaped tbsp each), placing them evenly over 2 baking trays lined with baking parchment, then bake for 25–30 minutes or until golden brown. You may need to turn the tray around halfway through to ensure they cook evenly in the oven. Place the baking tray on a cooling rack and leave to cool.
To make the buttercream, beat the butter in a large mixing bowl (or use a food mixer fitted with the beater attachment), then gradually add the rum. Now add the icing sugar and beat again until thoroughly combined. Be careful not to overwork the buttercream, as it will likely split.
Once the biscuits are cool, carefully remove them with a palette knife. Turn half of them over and spread a thick layer of buttercream on the flat sides, then sandwich together with the flat sides of the remaining biscuits.