Custard Apple and Pear Crumble

Ingredients: For the Fruit Filling: 2 ripe pears, peeled, cored, and sliced 2 custard apples (also known as cherimoya), peeled, deseeded, and scooped into chunks 1/4 cup granulated sugar 1 teaspoon lemon juice 1 teaspoon vanilla extract 1/2 teaspoon ground cinnamon For the Crumble Topping: 1 cup all-purpose flour 1/2 cup rolled oats