Chocolate s’mores cake

Heat the oven to 180C/fan 160C/gas 4. Oil and base line 2 x 20cm deep, round cake tins with baking paper. Mix the flour, cocoa, baking powder, bicarb, sugar and ½ tsp salt in a big mixing bowl. Mix the Horlicks with 100ml of boiling water to dissolve, then whisk in the smooth biscuit spread, followed by the oil, buttermilk, vanilla extract and finally the eggs.

Pour the wet ingredients into the dry and whisk until smoothly combined. Divide the mixture evenly between the tins, and bake for 20-25 minutes until risen and a skewer poked into the middle comes out clean. Cool in the tins for 10 minutes, then turn out onto a wire rack to cool completely.

To make the filling melt the chocolate in a heatproof bowl over a pan of barely simmering water. Remove and cool.

Put the butter and icing sugar in a bowl together and mash to combine, then beat with an electric whisk until smooth. Beat in the milk, followed by the melted chocolate, and finally fold in the smooth biscuit spread.

Spread one sponge with the all of the filling and scatter with the biscuit crumbs. Top with the second sponge and squidge down to stick.

To make the chocolate glaze put all the ingredients into a small pan with 4 tbsp water. Heat very slowly until the chocolate melts and you get a shiny sauce. Cool until thick enough to coat a spoon and drip off slowly, then spoon over the top of the cake and let it dribble down the sides.

Arrange the marshmallows on top of the cake, then use a blowtorch on its lowest setting to gradually melt and brown them. Once the marshmallows are toasted on top and melting onto the sponge, leave to cool and set for 10 minutes or so, before eating.