01 - Preheat the oven to 350°F (175°C). Lightly grease a 2-quart baking dish with butter or nonstick spray.
02 - In a large mixing bowl, combine strawberries, granulated sugar, cornstarch, lemon juice, and vanilla extract. Toss gently until the strawberries are evenly coated. Spread the mixture evenly in the prepared baking dish.
03 - In a separate bowl, mix rolled oats, all-purpose flour, brown sugar, salt, and cinnamon. Add the cold, cubed butter and blend using a pastry cutter or fork until the mixture resembles coarse crumbs.
04 - Evenly sprinkle the crisp topping over the strawberry filling. Bake in the preheated oven for 35 minutes, until the topping is golden brown and the filling is bubbling.
05 - Allow to cool for at least 15 minutes before serving. Enjoy warm, optionally topped with vanilla ice cream or whipped cream.