oil, for greasing
200g/7oz gluten free self-raising flour
50g/1¾oz cocoa powder, sifted
1 tsp bicarbonate of soda
100g/3½oz lactose free butter, cubed
100ml/3½fl oz lactose free milk
3 large free-range eggs, beaten
½ cup sweet potato, finely grated*
2 very ripe bananas (approximately125g/4½oz peeled weight), mashed with a fork
*Do not exceed half a cup of sweet potato, as it is listed as a moderate Polyol.
Preheat the oven to 200C/180C Fan/Gas 6. Grease and line the base and sides of a 23cm/9in loose-based square cake tin with baking parchment.
Mix the gluten free flour, cocoa and bicarbonate of soda in a large bowl. Make a well in the centre.
Put the lactose free butter in a medium saucepan and melt over a low heat, stirring regularly.
Take the pan off the heat and stir the lactose free milk into the melted lactose free butter.
Add the eggs, sweet potato and banana, stirring vigorously.
Pour slowly into the gluten free flour mixture, stirring constantly with a wooden spoon to form a thick batter. Pour into the prepared tin.
Bake in the centre of the oven for 30-35 minutes, or until the cake is risen and just firm to the touch.
Serve warm or leave to cool in the tin before cutting into squares.
Recipe adapted from: Good Food