1/2 cup butter
1 cup sugar
1 teaspoon vanilla extract
rind from one large lemon
2 large eggs, separated
1 1/2 cups all-purpose flour
2 teaspoons baking powder
1/2 cup milk
Ingredients for the fruit:
3 or 4 baking apples (enough to completely cover the batter)
Juice of one lemon
1/3 cup all-purpose flour
1/3 cup granulated sugar
1 teaspoon cinnamon
1/4 cup cold butter, cut into pieces
1/4 cup slivered almonds
Have the ingredients at room temperature before beginning to make the cake. Preheat the oven to 350°F/180°C. Grease a square pan or a round cake pan.
Make the streusel topping:
In a large bowl, mix together the flour, sugar, almonds and ground cinnamon. Cut in the butter with a pastry blender or fork until it resembles coarse crumbs. Set aside while you make the cake batter.
Prepare the fruit topping:
Peel the apples and cut them in quarters. Slice each quarter lengthwise into four pieces. Place the apples in a bowl, pour the lemon juice over them and mix well. Cover with plastic wrap and set aside. The lemon juice will give a wonderful flavour to the apples and it will also prevent them from browning while the batter is being made.
Make the batter:
- Cream the butter.
- Add the sugar and beat until light and fluffy.
- Scrape down the sides of the bowl and beat in the vanilla and lemon peel.
- Add the egg yolks one at a time, beating well after each addition.
- Add the flour in three batches, alternating with the milk and ending with the flour. Do not over-beat, beat only until combined.
- In a separate bowl whisk the egg whites until stiff peaks are formed.
- Very gently, fold the egg whites into the batter in two additions.
- Spread the batter onto the bottom of the prepared pan, smoothing the top with an offset spatula.
- Arrange the apples evenly on the batter.
- Sprinkle the streusel topping over the apples.
- Bake for about 50 minutes or until a toothpick inserted in the centre of the cake comes out clean.
- Remove from the oven and let the cake cool. Serve warm or at room temperature.