🍇 Prepare the filling
In a large bowl, gently toss the berries with sugar, cornstarch, lemon juice, vanilla, and a pinch of salt. Pour into a greased 9x9-inch (or similar) baking dish.

🥣 Make the topping
In another bowl, mix the oats, flour, brown sugar, nuts (if using), cinnamon, and salt. Drizzle in the melted butter and stir until the mixture becomes crumbly.

🍯 Assemble
Sprinkle the crisp topping evenly over the berry mixture.

🔥 Bake
Bake at 350°F (175°C) for 35–40 minutes, or until the berries are bubbling and the topping is golden brown.

❄️ Cool slightly
Let it cool for about 10 minutes before serving. The filling will thicken as it rests.

🍨 Serve
Delicious on its own or topped with vanilla ice cream, whipped cream, or Greek yogurt.

💡 Tips:
Using frozen berries? No need to thaw—just add 1 extra teaspoon of cornstarch.
Add a splash of balsamic vinegar to the fruit for a deeper flavor.
For a gluten-free version, use almond flour or a gluten-free blend and certified GF oats.