CALL me old fashioned, but I do love a black forest gateau, so work on a simple chocolate sponge, but make an amazing decoration to go around the outside of the gateau – think Great British Bake Off showstopper! Make a simple chocolate sponge and bake in two, 23cm greased cake tins. Make the filling by draining the juice from 2×390g jars of black cherries in kirsch, roughly chop the cherries. Mix 2 heaped tbsp. of cornflour with a little of the reserved cherry juice, place in a saucepan with the remaining juice, simmer until thickened, add the chopped cherries back in and leave to cool. Fridge till cold. Cut each sponge in to 2 layers, spread 3 layers with your reserved cherries and cover with whipped cream. Stack up the gateau and top with the plain sponge layer. Spread a good amount of whipped cream over the top and around the sides of your gateau, then with more whipped cream, pipe rosettes around the top edge of the gateau. For the garnishes, dip 12 fresh cherries in melted white chocolate and 12 fresh cherries in dark chocolate. On a credit card sized piece of card, draw a neat Christmas tree shape. Lay a length of baking parchment over the card and with some melted chocolate in a little piping bag, pipe 12 chocolate Christmas trees on the parchment paper. Leave the chocolate to set. Decorate the top of the gateau with the dipped cherries and decorate the sides with your piped chocolate Christmas trees!