Pre-heat your oven to 190°C (375°F).

In a pot, combine all ingredients for the apple filling, except the corn flour and water mixture. Mix together and heat on medium until the apples soften to your preference.

Add the corn flour and water mixture to the apples and stir until the mixture thickens, about 30 seconds. Leave aside.

In a small bowl, mix together all crumble ingredients except for the melted butter.

Pour in the melted butter and mix until crumbly.

In an oven-safe ramekin, layer the apple filling and then top with the crumble mixture.

Bake for around 15 minutes, or until the crumble is golden brown.

Allow to cool for a few minutes before serving with custard or ice cream.