Heat oven to 195C/175C fan/gas 5 ½. Butter and line the base of three 20cm round cake tins. Add the grated ginger to the grated pear and push down with a wooden spoon to squeeze out as much juice as possible.

Mix the flours, spices, baking powder and 1 tsp salt in a bowl. In a stand mixer, vigorously whisk the eggs and sugars for 3 mins until thick and frothy. Slowly pour in the oil in a steady stream. Turn the speed down, then add the flour mixture, 2 tbsp at a time, alternating with the yogurt, until incorporated. Mix in the grated pear (for no longer than 20 secs). Divide the mixture between the tins and bake for 25-30 mins or until a skewer inserted comes out dry.

For the caramel, heat the pear juice and perry in a pan until reduced to about 50ml. Add the sugar and butter and whisk to a smooth caramel, then add the cream and whisk again until smooth. Add sea salt to your taste – I’d go for a generous pinch, so that the caramel is still fruity and sharp but has a little saltiness to it – then allow to cool slightly to just warmer than room temperature.

To make the buttercream, put the egg whites and sugar in the bowl of a stand mixer. Place the bowl over a pan of boiling water, then whisk until the sugar dissolves and the mixture is no longer gritty. Put the bowl in the mixer, then whisk until soft peaks form and the bowl returns to room temperature. Switch to the paddle attachment, then add the butter, one spoonful at a time. Add the tahini, vanilla and a pinch of salt, and beat to a light, fluffy icing.

Place the bottom layer of sponge on a platter or cake stand, then top with a layer of the buttercream and scatter over a third of the chopped pear. Repeat with the next two layers. To ice the cake, do an intial layer all over, chill in the fridge for 20 mins, then use the remaining icing to cover everything. Use a stepped spatula to spread it out evenly. Pour the caramel over the top of the cake, and allow it to drip down the sides. Scatter with toasted buckwheat, dehydrated pear and rosemary, if you like.