My mum's amazingly delicious 'simple cake' – here baked as a blood orange and chocolate marble cake with rich chocolate glaze. You can vary the flavours and icing to your taste.
Preheat the oven to 180C | 350F. Line a large loaf tin with baking paper letting the paper hang over the edges.
In a stand mixer, whisk the egg whites and salt until you have stiff peaks. Transfer to another bowl and set aside.
Put the butter and sugar in the stand mixer bowl (no need to clean). Beat the butter and sugar for several minutes until creamy and white. Stop the mixer and scrape down the sides as you mix.
Add the egg yolks, one at a time, waiting until each is blended in before adding the next.
Combine the orange juice, milk, zest, vanilla extract and bicarbonate of soda in a measuring jug. The soda will cause the mixture to froth slightly.
Alternate adding the flour and orange mixture while mixing at low speed. Stir in the baking powder.
Gently fold in the whisked egg whites, in stages, with a large spatula until the batter is smooth.
Transfer 3/4 of the batter into the prepared tin. Mix the rest of the batter with the cocoa powder until smooth.
Feather the cocoa batter mixture into the cake using a knife to create the marbled effect, making sure it is mixed in well.
Bake for 45m - 1 hour until a skewer inserted in the centre comes out clean. Cool on a wire rack.
Put the chopped chocolate in a small bowl. Heat the cream and golden syrup until almost boiling then pour over the chocolate.
Leave to stand for a couple of minutes then stir until silky smooth. Pour or spread over the cooled cake and serve immediately.