Twinkly Swiss Chocolate Ganache Roll

For the sponge:

Using an electric hand mixer, whisk the eggs and sugar together in a large bowl until thick and creamy. Sieve the flour and cocoa together and fold into the egg and sugar mixture with the hot water, trying not to knock out too much air.

Place the sponge mixture into the prepared tin and tilt the tin to level the mixture, making sure it goes right into the corners. Bake at 160ºC (or 320ºF) for 12-15 minutes or until it is springy to the touch.

To form the roll shape, turn the sponge out onto a piece of baking parchment, and make a dent along the width of the sponge, 1cm in from one of the longest edges. From this same end, roll up the sponge into a long thin sausage shape with the paper in the middle, and twist the overlapping ends of the baking parchment like a sweet and leave it to cool on a wire rack. I also covered mine with foil to hold the shape firmly.

For the chocolate butter filling:

Beat the butter and icing sugar together until light and fluffy and then beat in the melted chocolate. Unroll the sponge from its wrappings, spread over the butter icing and roll up again, using the paper to support the sponge and protect from breakage. Cover with foil again and set to one side whilst you make the chocolate ganache frosting.

For the chocolate ganache frosting:

Place chocolate in a large heatproof bowl. Bring the double cream and the corn syrup to a simmer over medium-high heat in a nonstick saucepan on the hob; pour the sugar and cream mixture over chocolate and leave it to stand, without stirring, until chocolate begins to melt.

Stir the melted chocolate into cream until mixture is combined and smooth, stop as soon as you achieve a glossy, well mixed finish.

Refrigerate the mixture in a Tupperware container, until the frosting begins to thicken and becomes lighter in colour. Remove the chocolate Swiss roll from its foil and cover the entire thing with a 1cm thick layer of chocolate frosting. Sprinkle with a little icing sugar and some edible glitter.

Tips:

This entire recipe would work incredibly well as a white chocolate version. Add a little vanilla essence to the sponge mix and substitute the chocolate cocoa for white chocolate powder or Ovaltine in the sponge mix. Substitute the chopped hard chocolate in the chocolate cream and frosting for white chocolate. To finish, omit the icing powder sprinkles and instead, use a little vanilla sugar and some cute pink edible glitter for some Barbie-inspired glam!

On either version, use a packet of licorice allsorts to turn this cake into a hungry crocodile birthday cake. Cut the square allsorts in half diagonally and use to make teeth 1/3 of the way along the cake and halfway down as teeth. Use the licorice roll shapes as feet on either side, top and bottom. Use the pink and blue bobble-covered allsorts as eyes. This snappy sweet crocodile cake will bring toothy grins from children and adults alike!