Preheat oven to 350 degrees, and grease a large baking dish with butter.
Combine the chopped strawberries and sugar in a large bowl and mix well. Add the cornstarch and vanilla extract and stir until all of the strawberries are evenly coated. Pour into the prepared baking dish.
In a separate medium size bowl, combine the flour, oats, brown sugar, granulated sugar, salt, and cinnamon. Pour in the melted butter and stir well until well coated and crumbly. Sprinkle the crumb mixture evenly over the top of the strawberries.
Bake in the preheated oven for 35-40 minutes until fruit is bubbly and topping is golden brown. Allow to cool slightly before serving. Serve warm with vanilla ice cream on top. Enjoy!