Try this with currants or cranberries in place of sultanas.
2 medium potatoes, peeled
½ cup sugar
1 cup sultanas
¼ cup chopped peel
1 ½ cups milk
zest of lemon and 1 tablespoon juice
3 cups self-raising flour
Crumble Topping (see below)
Preheat oven to 180C (160C fan forced). Grease and line a 22cm x 32cm shallow baking pan. Cook potatoes in boiling water until tender, drain, cool and place into a large bowl.
Mash the potatoes, add the sugar and beat well. Add in the sultanas, peel, milk, lemon zest and lemon juice. Sift in flour and fold through. Spread evenly into the prepared pan.
Sprinkle Crumble Topping over the cake and bake for 45-50 min. Remove from the pan and cool completely. Cut into squares to serve.
Sift ½ cup self-raising flour into a bowl, add ½ cup sugar and 2 teaspoon nutmeg or cinnamon. Rub in 55g chopped butter until mixture resembles fine breadcrumbs.