Preheat Oven:Set your oven to 350°F and grease a 9x9 or 11x7 baking dish, or a 10-inch oven-safe skillet. Avoid larger pans like a 9x13 or 12-inch skillet, as they’ll be too big for this recipe.
Make the Blueberry Filling:In a large bowl, gently toss the blueberries with sugar, lemon juice, lemon zest, cornstarch, and cinnamon until evenly coated. Alternatively, you can mix everything directly in the baking dish.
Assemble the Filling:Pour the blueberry mixture into the prepared dish, spreading it out into an even layer.
Prepare the Oat Topping:In a separate bowl, mix the oats, flour, brown sugar, and salt. Add the melted butter and stir until combined. Mix in the almond extract for an extra flavor boost.
Add the Topping:Sprinkle the oat topping evenly over the blueberry filling.
Bake:Place the dish in the oven and bake for 40–45 minutes, or until the topping is golden brown and the blueberry filling is bubbling around the edges. If the topping browns too quickly, cover it loosely with aluminum foil.
Cool and Serve:Let the blueberry crisp cool for at least 10 minutes before serving. Enjoy it warm with a scoop of vanilla ice cream or a dollop of whipped cream for the ultimate treat!