Ingredients
Method
1.Preheat oven to 180°C, butter a 20cm round or square tin, or a ring tin, and line the base with baking paper. Have the egg and milk at room temperature. Dissolve the baking soda in the milk.
2.Put the flours, brown sugar and baking powder in a large bowl or food processor and combine them well. Rub in the butter until the mixture forms very fine crumbs.
3.Pour half of the crumbs into the prepared tin and press them down evenly to compact them. (You could weigh the mixture before you halve it if you want to be really accurate.)
4.Now beat the egg lightly and mix in the milk mixture and the grated nutmeg. Add this to the remaining crumbs and mix well with a wooden spoon, then pour the batter into the tin. It will be very liquid, but don’t worry: this makes a moist cake.
5.Sprinkle with the walnuts and bake for about an hour, rotating after 30 minutes.
6.Cool on a wire rack before carefully removing it from the tin. Stored airtight, this cake keeps for at least a week.