Prepare the Apple Filling

Cup of Yum
1. Preheat oven to  200°C/400°F/gas 6.
2. Peel and core the apples cut them in halves and slice them. Alternatively, you can cut them into 3 cm- 1" sized cubes.
3. Place the apples, sugar, cinnamon, and lemon juice into a medium-sized saucepan and cook it on medium heat until the apples are slightly softened and the juice from the apples is reduced to syrup.
4. Let the mixture cool down for 10 minutes while preparing the crumble mixture.

Prepare the Streusel Topping

1. Cut the butter into small cubes and place them in a mixing bowl with the flour and rub them together with your fingertips until it looks like bread crumbs.
2. Add the sugar (and vanilla if you wish) to the crumb and lightly rub the mixture with your fingertips until combined, without overworking it.

Cook The Apple Crisp

1. Transfer the apple filling into a 20cm x 30cm (8' x 12") baking dish.
2. Sprinkle the crumble over the apple filling and spread it evenly, gently pressing with your fingertips.
3. Bake in the oven for 25 to 30 minutes or until it looks golden brown. Let it rest for 5-10 minutes before serving. 
4. You can serve it with either vanilla ice cream or custard (or both!).