1. Grease and line a 22cm cake tin and heat the oven to 200¡C.
2. Melt the butter and milk together, being careful not to bring the milk to the boil, then set aside to cool.
3. Whip the eggs and sugar in a stand mixer until fluffy and pale, then sift in flour and baking powder. Fold together with a spatula, then add milk and butter mixture and zest. Fold gently with a spatula, then pour into cake pan.
4. Bake for 25 to 30 minutes until a skewer turns out clean, and allow to cool completely.
5. In a large measuring jug, whisk the three milks and malt together until combined then set aside.
6. When the cake is cool, slice off the browned edges and poke holes in the cake with a toothpick. Pour the milk mixture over the cake to soak and chill in the fridge for 3-4 hours.
7. Cut cake into portions then serve.