Preheat the oven to gas 3/160 c/150.
Prepare a regular sized bundt tin - 2.4l, 10 cup, 10 inch with melted butter and dust with flour. I’ve used the Nordicware Autumnal Wreath tin.
Cream the butter and sugar until pale and fluffy. Add the eggs one at a time, beating well after each addition.
In a separate bowl, measure out the flour, bicarbonate of soda, salt and spices. Pour the yoghurt into a jug, and add the apple sauce and vanilla extract. Sift in a third of the flour mix followed by half the yoghurt. Repeat this until everything is combined. Stir in the grated apple.
Give everything a quick mix on a low speed for about 10 seconds.
Pour the mix into your prepared tin. Bake in the centre of the oven for about 1 hour 15 minutes or until a skewer comes out clean.
Leave the cake to cool for ten minutes before removing from the tin. When completely cool, warm the caramel in the microwave to loosen its texture. When it’s runny, tip over the cake, and let gravity cover it.