Step 1

Adjust the oven rack to the middle position, pre-heat the oven to 350ºF (180ºC) and line two 6 inch (15cm) round cake tins with baking/greaseproof paper.

Step 2

In heat-proof bowl above a pot of simmering water (or in a microwave-safe bowl in the microwave), melt the chocolate and butter together. Set aside to cool until warm.

Step 3

In a large bowl, sift together the gluten free flour blend, caster/superfine (or granulated) sugar, cocoa powder, baking powder, baking soda, xanthan gum and salt.

Step 4

In a separate bowl or jug, whisk together the milk, water, oil and egg.

Step 5

Add the melted chocolate and the wet ingredients to the dry, and whisk well until you get a smooth, glossy and fairly runny chocolate cake batter with no flour clumps.

Step 6

Evenly divide the cake batter between the two lined cake tins and smooth out the top.

Step 7

Bake at 350ºF (180ºC) for about 26-28 minutes or until well risen and an inserted toothpick comes out clean.

Step 8

Allow to cool in the cake tins for about 10 minutes before turning them out onto a wire cooling rack to cool completely.

Step 9

In a large bowl, combine all the frosting ingredients and mix (with a rubber spatula) or whisk (with a balloon whisk) well until you get a smooth, glossy and fairly thick frosting that is easily spreadable.

Step 10

Level off the sponges with a sharp serrated knife.

Step 11

Place the bottom sponge on a cake stand or serving plate of choice.

Step 12

Dollop some of the frosting on top and smooth it out into an even layer, using a small offset spatula.

Step 13

Place the other sponge on top, with the bottom of the sponge facing upwards (this will give you a nice flat top).

Step 14

Use most of the remaining frosting to cover the outside of the cake (reserve some for piping the decorations on top). Smooth out the sides and top as much as you can – but don’t worry about it being 100% perfect.

Step 15

Transfer the leftover frosting into a piping bag fitted with a star nozzle of choice, and decorate the cake with swirls and dollops of frosting. If you want, you can finish it off with some sprinkles (optional) before slicing and serving.Tip: For extra neat and clean slices, cut the cake with a warm/hot knife. Choose a sharp knife and dip it into very hot water. Wipe it dry, then slice the cake while the knife is still hot/warm. In between slices, dip the knife again in hot water, wipe it off and repeat.

Step 16

The gluten free chocolate cake keeps well in a closed container in the fridge for 3-4 days.