Heat the oven. Set it to 375°F (190°C). Lightly butter a 9-inch square baking dish or similar 2-quart dish.

Prep the berries. If using strawberries, hull and slice them. If using frozen berries, use them straight from the freezer. Toss the berries with the sugar in the baking dish. If you have it, add lemon zest or a squeeze of lemon to lift the flavor.

Make the crumble topping. In a bowl, combine the flour and a pinch of salt. Add the cold butter cubes. Use your fingers or a pastry cutter to rub the butter into the flour until coarse crumbs form. You’re looking for a mix of sandy bits and small pea-sized clumps.

Top the berries. Sprinkle the crumble mixture evenly over the sugared berries. Don’t pack it down—those loose crumbles bake up crisp.

Bake. Place the dish on a rimmed baking sheet to catch any bubbling juices. Bake for 35–45 minutes, until the fruit is bubbling around the edges and the topping is golden brown.

Rest before serving. Let it cool for at least 10–15 minutes. The juices will thicken as it sits, making it easier to scoop.

Serve. Enjoy warm as is, or add vanilla ice cream, whipped cream, or Greek yogurt.