Preheat your oven to 350℉ (175℃/Gas Mark 4), then butter a 9-10 inch pan or 1.5-2 quart casserole dish.
In a medium to large-sized mixing bowl, add the 5 cups blackberries and 4 Tbsp sugar, plus the optional lemon zest or lime. Stir gently to coat the berries.
In another mixing bowl, combine the dry ingredients: 2 cups all-purpose flour, 2 cups rolled oats, 1½ cups light brown sugar, 1 tsp cinnamon, and ½ tsp nutmeg. Mix the evenly distribute the ingredients.
Add the cold 1½ cups butter and use a pastry cutter to cut it in until it reaches pea-sized crumbles.
Add the sugared blackberry mix to your prepared baking dish, making an even layer that covers the bottom. Top the berries with the dry crumble oatmeal streusel crust mixture.
Bake in preheated oven at 350℉ (175℃/Gas Mark 4) for 40-45 minutes or until berries are bubbling around the edges and the topping is golden brown.
Remove from the oven when done and cool for 5 minutes before serving while warm.
Preheat your oven to 350℉ (175℃/Gas Mark 4), then butter a 9-10 inch pan or 1.5-2 quart casserole dish.
In a medium to large-sized mixing bowl, add the 5 cups blackberries and 4 Tbsp sugar, plus the optional lemon zest or lime. Stir gently to coat the berries.
In another mixing bowl, combine the dry ingredients: 2 cups all-purpose flour, 2 cups rolled oats, 1½ cups light brown sugar, 1 tsp cinnamon, and ½ tsp nutmeg. Mix the evenly distribute the ingredients.
Add the cold 1½ cups butter and use a pastry cutter to cut it in until it reaches pea-sized crumbles.
Add the sugared blackberry mix to your prepared baking dish, making an even layer that covers the bottom. Top the berries with the dry crumble oatmeal streusel crust mixture.
Bake in preheated oven at 350℉ (175℃/Gas Mark 4) for 40-45 minutes or until berries are bubbling around the edges and the topping is golden brown.
Remove from the oven when done and cool for 5 minutes before serving while warm.