Make the Sponge: Preheat your oven to 180°C (160°C fan). Grease and line a 20cm square baking tin. In a large bowl, cream the butter and caster sugar together until pale and fluffy. Beat in the eggs one at a time, then fold in the flour, baking powder, and orange zest until just combined. Spoon into the prepared tin and bake for 25-30 minutes, or until a skewer inserted into the centre comes out clean. Let it cool completely.

Prepare the Cranberry Compote: While the sponge bakes, place the cranberries, sugar, and orange juice in a medium saucepan over a medium heat. Bring to a simmer and cook for 8-10 minutes, stirring occasionally, until the berries have burst and the sauce has thickened slightly. Set aside to cool completely.

Start the Custard: Pour the milk and 250ml of double cream into a saucepan. Add the split vanilla pod (or paste) and gently heat until it's just about to simmer. Remove from the heat and let it infuse for 10 minutes.

Finish the Custard: In a large bowl, whisk the egg yolks, sugar, and cornflour together until pale and smooth. Remove the vanilla pod from the milk mixture, then slowly pour the warm milk over the egg mixture, whisking constantly. For a more detailed guide on this technique, BBC Good Food has an excellent visual step-by-step.

Thicken the Custard: Pour the mixture back into the clean saucepan and cook over a low-medium heat, stirring continuously with a wooden spoon or spatula for 6-8 minutes, until it thickens enough to coat the back of the spoon. Do not let it boil.

Add the White Chocolate: Remove the custard from the heat and add the chopped white chocolate. Stir until the chocolate has completely melted and the custard is smooth and glossy. I find that pouring it through a fine-mesh sieve into a clean bowl ensures a perfectly silky texture. Cover the surface directly with cling film to prevent a skin from forming and let it cool completely.

Assemble the Trifle: Cut the cooled sponge into 3cm cubes. Arrange half of the sponge cubes in the bottom of a large glass trifle bowl (around 3-litre capacity). Drizzle over half of the Cointreau or orange juice. Spoon over half of the cooled cranberry compote, followed by half of the white chocolate custard. Repeat the layers with the remaining sponge, liqueur, compote, and custard.

Chill Thoroughly: Cover the trifle bowl with cling film and place it in the fridge to chill for at least 6 hours, or preferably overnight. This is a crucial step that allows the sponge to soften and the flavours to mingle.

Decorate and Serve: Just before serving, whip the 500ml of double cream with the icing sugar until it forms soft peaks. Spoon or pipe the cream over the top of the trifle. Decorate with a generous scattering of white chocolate curls and a few fresh cranberries. For a festive touch, you could also add some sugared rosemary sprigs.