Preheat your oven to 375°F (190°C). Lightly grease a 9x9-inch baking dish or a 1.5-quart baking dish.

In a large bowl, gently toss the strawberries with granulated sugar, cornstarch, lemon juice, and vanilla extract until evenly coated. Let sit for 5 minutes to release juices.

In a separate medium bowl, whisk together flour, oats, brown sugar, and salt. Add the cold butter cubes and use a pastry cutter or your fingertips to work the butter into the dry mixture until it resembles coarse crumbs with some pea-sized butter pieces.

Pour the strawberry mixture into the prepared baking dish and spread evenly. Sprinkle the crumble topping evenly over the strawberries.

Place the dish on a baking sheet to catch any drips. Bake for 30–35 minutes, until the filling is bubbly and the topping is golden brown. Let cool for 5–10 minutes.

Spoon the warm crisp into bowls and top each serving with a generous scoop of vanilla ice cream. Serve immediately.