Step 1: Preheat oven to 375°F (190°C). Lightly grease an 8x8 inch or 9-inch round baking dish.
Step 2: In a large bowl, combine the pitted cherries, 1/2 cup granulated sugar, cornstarch, lemon juice, and almond extract. Toss gently until cherries are evenly coated.
Step 3: Pour the cherry mixture into the prepared baking dish, spreading it out evenly.
Step 4: In a separate medium bowl, whisk together the all-purpose flour, rolled oats, brown sugar, 1/4 cup granulated sugar, cinnamon, and salt.
Step 5: Add the cold, cubed butter to the dry ingredients. Using your fingertips, a pastry blender, or two knives, cut the butter into the mixture until coarse crumbs form with some pea-sized pieces remaining.
Step 6: Sprinkle the crumble topping evenly over the cherry filling in the baking dish.
Step 7: Bake for 40-50 minutes, or until the topping is golden brown and the cherry filling is bubbly and thickened. If the topping browns too quickly, loosely tent with foil.
Step 8: Remove from oven and let cool on a wire rack for at least 15-20 minutes before serving to allow the filling to set.