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