Preheat your oven to 180°C/Gas 4. Line your loaf tin with baking parchment.

Finely zest and juice the orange. Grate the apples, with their skins on, and measure 200g into a small saucepan. Add half the orange juice (reserving the rest for later) and cook over a gentle heat for 3-4 mins, until the apple has started to soften. Remove from the heat and keep to one side.

Peel the thinner end of the squash and coarsely grate 200g of it. Roughly chop the walnuts and sultanas. Separate your eggs out into the yolks and whites.

Place the oil and sugar into a large mixing bowl and whisk together. When they look creamed and well mixed, whisk in the egg yolks. Stir in the cooked apple, squash, walnuts, sultanas, spices, bicarb and a pinch of salt.

In a separate, clean bowl, whisk the egg whites until light, fluffy and just forming stiff peaks.

Sift the flour into the bowl of wet ingredients. Fold it in with a large spoon until no dry patches appear; take care not to overmix. Next, fold in the egg whites until the mix is evenly combined. Do not beat or whisk the mixture, as you don't want to knock too much air out of the egg whites.

Scrape the mix into the loaf tin, level it with the back of a spoon, transfer to the oven and bake for 1 hour, or until a skewer or knife tip comes out clean. Cover it loosely with foil at the halfway point to avoid the top becoming too dark. Leave in the tin to cool completely.

Mix the remaining orange juice and zest with the 2 tbsp of sugar. Pour over the top of the cake as it cools.