Making Blackberry Crisp is a breeze if you follow these simple steps:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C).
2. Prepare the Blackberries: In a large bowl, combine the blackberries, 1/2 cup granulated sugar, cornstarch, lemon juice, and vanilla extract. Gently toss to coat the blackberries evenly.
3. Transfer to Baking Dish: Pour the blackberry mixture into a greased 9×13-inch baking dish, spreading it out evenly.
4. Make the Crisp Topping: In a separate bowl, mix the rolled oats, flour, brown sugar, cinnamon, and the remaining 1/2 cup of granulated sugar.
5. Add the Butter: Using a pastry cutter or your fingers, cut in the cold butter until the mixture resembles coarse crumbs.
6. Top the Blackberries: Sprinkle the topping evenly over the blackberry mixture in the baking dish.
7. Bake: Place the dish in the oven and bake for 30 minutes, or until the topping is golden brown and the blackberries are bubbling.
8. Cool: Remove from the oven and let cool for a few minutes before serving.

These steps will guide you through creating this incredible dessert with ease.