Blueberry crisp is the perfect dessert when fresh blueberries are in season. It only requires a few pantry staples and takes just a few minutes to assemble before popping it in the oven — no fussing with making pie crust! I love serving mine warm with a scoop of vanilla ice cream for an easy summer dessert.
FAQ
Can I use frozen blueberries to make blueberry crisp?
Yes, you can use frozen blueberries in this recipe! Keep in mind that frozen berries release a little more liquid as they bake, so I recommend adding an extra teaspoon or two of cornstarch. You may also need to bake the crisp for a few extra minutes to account for the colder berries.
Why is my blueberry crisp runny?
Blueberry crisp is naturally quite runny when it’s fresh out of the oven, so don’t worry if the filling seems a little loose at first. As it cools, the cornstarch continues to set, creating a thicker filling. For the best texture, let the crisp rest for 30 to 45 minutes before serving.
If the filling is still very runny after cooling, it may not have baked long enough. Make sure it’s bubbling around the edges before removing it from the oven.
Can I make blueberry crisp ahead of time?
Yes, you can absolutely make blueberry crisp ahead of time! Simply assemble the blueberry crisp up to a day in advance, cover it tightly with plastic wrap, and refrigerate it until you’re ready to bake.
You can also bake it ahead of time and gently reheat it in a 350°F oven until warmed through. Keep in mind that the topping has the best texture when it’s freshly baked!
Preparing the Streusel (Crumble Topping)
Preheat your oven to 350 degrees and place a baking sheet lined with parchment paper on the middle rack. (This acts as insurance against bubbling over!)
In the bowl of a stand mixer fitted with the paddle attachment, on low speed, mix the flour, brown sugar, granulated sugar, and salt until fully incorporated. Add in the oats and continue mixing just until evenly distributed.
Dice chilled butter into ¼” pieces and add them to the mixture. Continue mixing on low speed for about 3 to 5 minutes, until the mixture comes together in crumbles and no dry spots remain.
Note: The mixture may appear dry at first — that’s OK… just keep mixing!
Using your fingers, clump the mixture together to form chunks. Chill in the refrigerator while preparing the blueberry filling.
Preparing the Blueberry Filling
In a large bowl, whisk together the sugar, cornstarch, cinnamon, and salt until well combined.
Next, add in the blueberries, lemon zest, and lemon juice, and gently toss the mixture together until moistened.
Assembling and Baking the Blueberry Crisp
Pour the blueberry filling into a buttered 8″ square baking dish.
Sprinkle the crumble topping in an even layer over the blueberries, press it down gently.
Place the assembled blueberry crisp into the oven on your prepared baking sheet. Bake for 60 to 70 minutes, until the filling is bubbly and the top is golden brown.
Important note: Keep an eye on the topping! If at any point it begins to brown too quickly, carefully place a piece of aluminum foil over the top while continuing to bake.
Once baked, remove the crisp from the oven and place it on a wire rack to cool for at least 30 minutes before serving. Remember, the blueberry filling will continue to thicken as it cools, so it may be runny if served hot out of the oven.
Allow any leftover crisp to cool completely before covering the baking dish with plastic wrap (or moving the mixture into an airtight container) in the refrigerator. To reheat, remove the plastic wrap, cover the crisp with foil, and heat it in a 350℉ oven until warmed through.
Blueberry Crisp
Ingredients
For the Blueberry Filling
- 6 cups (3 pints) fresh blueberries
- 1 tsp lemon zest
- 1 ½ Tbsp freshly squeezed lemon juice
- ½ cup granulated sugar
- 2 Tbsp cornstarch (use 1 ½ Tbsp if you prefer a looser filling; see Note 1)
- 1 tsp ground cinnamon
- ⅛ tsp kosher salt (I use Diamond Crystal)
For the Streusel (Crumble Topping)
- ¾ cup all-purpose flour (spooned and leveled)
- ⅓ cup light brown sugar, packed
- ¼ cup granulated sugar
- ¼ tsp kosher salt
- 1 cup oats (rolled or large flake)
- 8 Tbsp (1 stick) unsalted butter, chilled and cut into ¼" cubes
Instructions
Preparing the Streusel (Crumble Topping)
- Preheat the oven to 350℉. Line a baking sheet with parchment paper and place it on the middle rack (to catch any spills that may bubble over).
- In the bowl of a stand mixer fitted with the paddle attachment, mix the flour, brown sugar, granulated sugar, and salt on low speed until fully incorporated. Add in the oats and continue mixing just until evenly distributed.¾ cup all-purpose flour⅓ cup light brown sugar, packed¼ cup granulated sugar¼ tsp kosher salt1 cup oats
- Add in the diced, chilled butter. Continue mixing on low speed until the mixture comes together into crumbles and no dry spots remain (about 3 to 5 minutes).Note: The mixture may appear dry at first — that’s OK… just keep mixing!8 Tbsp (1 stick) unsalted butter, chilled and cut into ¼" cubes
- Using your fingers, clump the mixture together to form small chunks. Chill the streusel in the refrigerator while preparing the blueberry filling.
Preparing the Blueberry Filling
- In a large bowl, whisk together the sugar, cornstarch, cinnamon, and salt until well combined.½ cup granulated sugar2 Tbsp cornstarch1 tsp ground cinnamon⅛ tsp kosher salt
- Add in the blueberries, lemon zest, and lemon juice. Gently toss the mixture together until all the berries are evenly coated and moistened.6 cups (3 pints) fresh blueberries1 tsp lemon zest1 ½ Tbsp freshly squeezed lemon juice
Assembling and Baking the Blueberry Crisp
- Pour the blueberry filling into a buttered 8" square baking dish.
- Sprinkle the streusel (crumble topping) in an even layer over the blueberries, gently pressing it down.
- Place the assembled blueberry crisp onto the prepared baking sheet in the oven. Bake until the filling is bubbly and the topping is golden brown (about 60 to 70 minutes).Important note: Keep an eye on the topping. If it begins to brown too quickly, carefully tent a piece of aluminum foil over the top while it finishes baking.
- Remove the blueberry crisp from the oven and place it on a wire rack to cool for at least 30 minutes before serving. (Remember, the blueberry filling will continue to thicken as it cools, so it may be runny if served hot out of the oven.)
- Allow any leftover crisp to cool completely before covering the baking dish with plastic wrap (or transferring it to an airtight container) and storing it in the refrigerator. To reheat, remove the plastic wrap, cover the dish with aluminum foil, and bake in a 350℉ oven until warmed through.
Notes
- Filling Thickness (using Cornstarch): I use 2 Tbsp of cornstarch in this recipe, which results in a medium-thick blueberry filling — not super runny, but also not sliceable like a pie. If you prefer your filling a bit looser, use 1 ½ Tbsp of cornstarch. Keep in mind that, in both cases, the filling will be runny fresh out of the oven since cornstarch thickens the filling as it cools.
