Apple crumble cake

Ingredients

• Crumble
• 3/4 cup self-raising flour
• 1 teaspoon ground cinnamon
• 1/3 cup white sugar
• 75 gram butter, chilled, chopped
• 220 gram butter, chopped, melted
• 4 eggs
• 2 3/4 cup self-raising flour
• 1 1/2 cup caster sugar
• 1 cup light sour cream
• 1/3 cup custard powder
• 1 teaspoon vanilla essence
• 1 quantity stewed apple
• thickened cream, whipped, to serve