01 -
In a large bowl, combine all-purpose flour, rolled oats, packed brown sugar, and ground cinnamon. Cut in softened butter until mixture forms coarse crumbs.
02 -
Spread the chopped, peeled apples evenly into a greased 2-quart baking dish.
03 -
In a small saucepan over medium heat, whisk together granulated sugar, cornstarch, and water. Bring to a gentle boil, stirring constantly, until thickened and clear. Remove from heat and stir in vanilla extract.
04 -
Sprinkle half of the crumb mixture over the apples. Pour the prepared syrup evenly over the apple and crumb layers.
05 -
Sprinkle the remaining crumb mixture over the apples and syrup.
06 -
Bake in a preheated oven at 350°F (177°C) for 60 to 65 minutes, or until apples are tender and the topping is golden brown.
07 -
Serve warm, optionally topped with a generous scoop of vanilla ice cream.