For the Filling:

• 2 cups fresh blackberries – Washed and gently patted dry.
• 1/2 cup granulated sugar – For sweetening the blackberries.
• 1 tablespoon lemon juice – Enhances the natural tartness of the blackberries.

For the Topping:

• 1 cup all-purpose flour – Forms the base of the crumble topping.
• 1/2 cup rolled oats – Adds a chewy texture to the topping.
• 1/2 cup brown sugar – Gives the crumble a rich, caramel-like sweetness.
• 1/2 cup cold unsalted butter – Cubed, ensuring the topping becomes perfectly crumbly.
• 1/2 teaspoon cinnamon – Adds warmth and depth to the dessert.
• 1/4 teaspoon salt – Balances the sweetness and enhances flavor.