Chocolate cake is globally renowned for its delicious cocoa flavour and when done right, moist sponge.

Many people have a ‘favourite’ recipe for making chocolate cake, but few like James Martin’s take on it.

Sharing his recipe on the BBC, James claimed: “Adding cola to this chocolate cake makes it incredibly moist and impossible to stop at one slice!”

The unique recipe uses the popular fizzy drink and caster sugar and milk for extra sweetness.

It uses cola in the frosting too, so the flavour doesn’t get lost in the sponge.

Ingredients

250g/9oz self-raising flour

300g/10½oz golden caster sugar

Three heaped tbsp cocoa

A generous pinch bicarbonate of soda

250g/9oz butter

250ml/8½fl oz cola drink

125ml/4¼fl oz milk

Two eggs, beaten

One tsp vanilla extract

For the topping

100g/3½oz butter

Two tbsp cola drink

Two tbsp cocoa

200g/7oz icing sugar

To serve

Caramel chocolate bar (king size)

Splash of double cream

Two tbsp mini marshmallows (optional)

Method

Heat the oven to 180C/350F/Gas mark 4, then take a large mixing bowl and sift in the flour, sugar and cocoa powder.

Add the bicarbonate of soda, then stir everything together until combined.

Take a medium-sized saucepan and melt the butter. Add the cola drink and stir gently. Add the wet ingredients to the bowl of dry ingredients, and follow with the milk, eggs and vanilla.

Mix the contents of the bowl gently but thoroughly then tip into a buttered, loose-based cake tin (24cm/9½ in diameter).

Bake for about 40 minutes or until a skewer inserted into the centre of the cake comes out clean. Remove the baked cake from the oven and leave for about 15 minutes. Meanwhile, make the topping.

Add the butter, cola drink and cocoa into a pan and melt slowly. Bring the mixture to a boil. Pour the icing sugar into a large mixing bowl and then pour the hot mixture over the top of it.

Beat until smooth and pour over the cake while still warm. Cool the cake in the tin.

Serve with the sauce, made by melting the chocolate bar gently in a pan with a splash of cream (you may want to add a little warm water to achieve a pouring consistency), then stir in the marshmallows if using.