Preheat the oven to 200ºC (fan 180ºC)/400ºF/gas mark 6. Grease a 900g (2lb) loaf tin with extra oil, then base-line with baking paper. Pour the oil and the sugar into a bowl and whisk until smooth. Add the eggs and continue mixing until you have a smooth, glossy mixture. Sift in the flour, baking powder and mixed spice and fold it in until well combined, then add the milk and grated beetroot. Mix to incorporate, then finally add the walnuts and hazelnuts.
Pour the mixture into the prepared loaf tin and bake in the preheated
oven for 30 minutes or until a skewer inserted in the centre comes
Cool on a wire rack. Remove the cake from the tin, peel off the paper and place on a serving plate. Heat the apricot jam in a small pan and glaze the cake with it, then use a Microplane to grate and sprinkle the top with the extra chopped nuts.