Preheat oven to 350°F (177°C). Butter an 8 x 8-inch baking dish; set aside.
Prepare Topping:
Whisk together flour, brown sugar, cinnamon, and salt in a medium bowl.
Stir melted butter into flour mixture, pressing until it clumps together. Set aside for 10 minutes.
Prepare Filling:
Wash berries, then blot dry with paper towels. If you're using strawberries, cut them into halves or quarters, depending on their size.
In a large bowl, combine the berries with the sugar, cornstarch, 1 tablespoon lemon juice, all of the lemon zest, and a pinch of salt. Mix well.
Assemble Crumble:
Transfer berries to buttered baking dish, spreading in an even layer. Scrape any juices / sugar that remain in bowl into baking dish.
Using hands, crumble topping mixture over fruit.
Bake until topping is browned and berries are bubbling, about 45 to 50 minutes.
Let cool for at least 30 minutes before serving. Serve plain or topped with ice cream. Enjoy!
Notes
I used light brown sugar, however dark brown sugar would also work.For a vegan / dairy free crumble, use plant based butter.If you'd prefer an oat-based topping, feel free to substitute my Oat Crisp Topping. It's delicious either way!Check out the info before this recipe card for helpful tips, variations, related recipes, and more!