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