Bonfire cake

Preheat the oven to 160°C, gas mark 3 and grease and line 3 x 18cm sandwich tins with baking parchment. Heat the butter, sugar, treacle and syrup together in a large saucepan, stirring until the butter is melted and the sugar has dissolved.

Take the pan off the heat. Pour and whisk the milk into the saucepan with the hot mixture, then beat in the eggs until well combined. Sift the flour, bicarbonate of soda and spices together into the saucepan and whisk together until smooth.

Divide equally between the tins and bake for 30-35 minutes, until firm and a skewer inserted into the centre comes out clean. Leave to cool briefly in the tins, then transfer to a wire rack to cool completely.

While the cakes cook, make the treacle toffee sauce. Place all the ingredients into a saucepan and heat gently until the sugar crystals dissolve. Turn up the heat and allow to boil for 5 minutes, or until the sauce thickly coats the back of a metal spoon. Pour into a jug, cool, then cover and chill until ready to use.

To make the buttercream, put the butter into a large bowl or the bowl of a stand mixer. Beat briefly to soften, then add the icing sugar in a few batches, making sure it’s incorporated before adding more. Beat for 5-10 minutes until pale and fluffy, then add 100ml cooled toffee sauce and beat for a few more minutes.

For the pecan brittle, line a baking tray with baking parchment and spread the pecans out over it. Mix the sugar with 2 tbsp water in a small saucepan, then heat gently until the sugar dissolves. Turn up the heat and boil, without stirring, until the caramel turns a deep amber, then pour the hot caramel over the pecans and allow to cool completely.

To assemble the cake, put the first layer on a cake stand and top with about a fifth of the buttercream. Use a palette knife to spread it to the edges of the cake, then top with the second layer of sponge. Repeat the buttercream process, then place the final layer on top. Cover the top and sides of the cake with buttercream, scraping the excess away from the sides with a large palette knife so they are thinly coated and the layers show through. The top should be smooth and the edges sharp. Chill the cake for at least 30 minutes for the buttercream to set.

Gently heat the remaining toffee sauce in the microwave until just pourable, but not warm enough to melt the buttercream. Pour the sauce into the centre of the cake and push to the edges, gently teasing it down the edges to create drips. Blowtorch the marshmallows to toast them and break the brittle into tall shards. Arrange them on top of the cake and scatter over the brittle crumbs and pecan halves. Add the sparklers (if using) just before serving.