Apple Streusel Cake
120g butter
1/2 cup brown sugar, firmly packed
1/4 teaspoon ground nutmeg
1 teaspoon ground cinnamon
3 green apples, peeled, cored, sliced into thin rings
2 teaspoons lemon juice
1 1/3 cups self-raising flour
1 3/4 teaspoons baking powder
3/4 cup caster sugar
1/4 teaspoon salt
1/2 cup milk
1 teaspoon vanilla essence
1 egg, separated
3/4 cup walnuts, chopped
Icing-sugar mixture for dusting
1. Grease a 19cm square cake pan; line the base and sides with baking paper.
2. Heat 60g butter, brown sugar and spices in a small pan; stir over a low heat until butter is melted and sugar is dissolved. Pour into prepared pan; arrange apple slices, overlapping, over butter mixture. Drizzle with lemon juice.
3. Combine sifted flour, baking powder, caster sugar and salt in a large bowl; rub in remaining butter until mixture resembles coarse crumbs. Add milk and vanilla essence; beat on low speed with an electric mixer for about 2 minutes or until combined. Add egg-yolk and nuts; beat for 1 minute.
4. Beat egg-white in a small bowl with an electric mixer until firm peaks form; gently fold egg-white into cake batter. Spoon mixture over apples in pan; smooth surface with spatula.
5. Cook in a moderately hot oven, 190C, for 35 minutes. Cover lightly with foil; cook for a further 15 minutes or until cooked when tested. Stand in pan for 5 minutes; carefully turn onto a serving plate.
6. Serve cake warm; dust with sifted icing-sugar mixture.