Preheat your oven to 170ºC/340ºF fanbake. Line the base of a 22cm/8½in springform cake tin with baking paper and grease the sides with butter.

If you haven’t already, slice the pears and place in a bowl of cold water to cover, with vinegar or lemon juice to stop them from browning. Set aside.

Place the flour, walnut flour, baking powder, and sugar in a mixing bowl and stir to combine. Add the butter and mix until evenly combined.

Firmly press 1 rounded cup of this mixture into the base of your prepared cake tin to form a biscuit base.

Gently heat the milk in a pot and whisk in the baking soda.

Add this mixture to your remaining walnut flour mixture, along with the egg, nutmeg, and ground ginger.

Mix until smooth. Gently fold in the walnut pieces with a spatula.

Pour half of this batter over the pressed crust.

Remove the pears from the vinegar water. Give them a shake and pat dry using a tea towel. Arrange half of the pears over the batter in a single layer.

Pour over remaining batter, and finish with the remaining sliced pears, fanning them out over the top of the cake in a single layer. They will sink into the batter, so don’t press them in. Sprinkle over raw sugar.

Bake in your preheated oven until the cake is risen, top is golden brown, and a skewer inserted into the centre comes out clean (40–45 minutes)

Allow the cake to cool in the tin before turning out.

You can easily make your own walnut flour by blitzing walnut pieces in a food processor. Be careful that you don't over-process and start making walnut butter.

Cake will keep in a sealed container in a cool dry place for 2–3 days, or in a sealed container in the fridge for up to a week.