Cook the cranberries. Simmer with the sugar, orange zest and juice, star anise and cinnamon 8-10 minutes until most have burst. Fish out the whole spices, stir in the slaked cornflour and cook 1 minute more until glossy.

Cool it completely. Spread it on a cold plate. Spooned on warm it will melt straight through the cheese layer and ruin the band.

Make the rubble. Pulse the pistachios and digestives in short bursts to a coarse rubble with some pieces still the size of a grain of rice. Blitzed to powder it sets like concrete and the fork will not go through it.

Bind it. Pour over the melted butter and stir until every crumb is darkened and the mixture clumps when you squeeze a handful. If it still falls apart, add melted butter a teaspoon at a time.

Press it in. Stand the rings on a lined tray. Spoon in the crust and press it flat with the base of a small glass, then push a little up the inside walls so the band shows from the outside. Chill 30 minutes until firm.

Start at room temperature. Take the brie, rind removed, and cream cheese out of the fridge an hour ahead. Cold cheese will not go smooth, and beating it harder to fix that only splits it.

Beat the brie, rind removed, and cream cheese alone first, on a low speed, for about two minutes until completely smooth with no lumps at all. This is the single step people skip and it is the one that decides the texture.

Add the thyme leaves and black pepper and beat again on low until the colour is even edge to edge, scraping the bowl twice. Taste and season now; once it is set you cannot change it.

Beating the brie smooth takes longer than you expect and is worth doing properly; it should look like thick paint before anything else goes in.

Whip the cream. Whisk the 100ml double cream to soft peaks - it should just hold its shape and still flop when the whisk comes out. Taken to stiff peaks it goes grainy and will not fold in cleanly.

Fold, do not beat, the whipped cream through in three additions with a spatula, cutting down through the middle and lifting over. Stop the moment it is even — every extra stroke knocks out the air that makes it light.

Check the consistency. It should drop slowly from the spoon and hold a soft ribbon on the surface for a second or two. Too loose and it will not stand; too stiff and it will trap air pockets. It should be pale cream.

Fill in two goes. Spoon half the creamy mixture over the chilled crust and tap the tray firmly on the worktop to drive out air pockets, then add the rest and tap again.

Level the top. Smooth it flat with a palette knife dipped in hot water and wiped dry. A flat top is what makes the finished tower look sharp rather than homemade.

Chill properly. Two hours is enough for an 8cm ring, and longer does no harm. Rushing this is why towers slump when the ring comes off.

Unmould cleanly. Run a thin knife around the inside of each ring, then warm the outside of the ring briefly with your hands and lift it straight up, slowly. If the sides smear, it needs another hour in the fridge.

Dress the top and serve at cool room temperature rather than fridge-cold, which mutes everything.