1. Preheat the oven to 160ÅãC, gas mark 2. Line a 12-hole muffin tin with paper cases. Put the maple syrup, milk, sugar, butter and chocolate in a saucepan over a low heat and stir until melted and smooth. Pour the mixture into a large bowl and allow to cool for 15 minutes. Add both the flours and whisk until just combined. Add the egg and whisk until smooth.
2. Divide the mixture between the paper cases. Bake for 25–30 minutes or until a skewer inserted into the centre comes out clean. Remove from the tin and allow to cool on a wire rack.
3. To make the caramel fudge frosting, put the sugar, butter and salt in a small saucepan over a low heat and stir until the sugar is dissolved. Increase the heat to high, add the milk and vanilla and bring to the boil for 3 minutes, stirring occasionally. Remove from the heat. Add the icing sugar and whisk until smooth. Working quickly, spread the cupcakes with the caramel fudge frosting and allow to set. If the frosting hardens before all the cakes are iced, place the saucepan over a medium heat and stir until the frosting is melted and smooth enough to spread again.