Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 unbaked 9-inch pie crust (homemade or store-bought)
- 6 cups (900 g) blueberries (fresh or frozen)
- 3/4 cup (150 g) granulated sugar
- 1/4 cup (32 g) cornstarch
- 1 tbsp lemon zest + 2 tbsp (30 ml) lemon juice
- 1/2 tsp ground cinnamon
- 1/4 tsp fine salt
- Streusel: 3/4 cup (90 g) all-purpose flour, 1/2 cup (100 g) packed brown sugar, 3/4 cup (75 g) rolled oats, 1/2 tsp cinnamon, 1/4 tsp salt, 6 tbsp (85 g) unsalted butter (cold)
- Optional finish: 1 tbsp (14 g) unsalted butter (to dot), 1 tbsp (12 g) coarse sugar
Do This
- 1. Chill crust in a 9-inch pie dish for 15 minutes; heat oven to 425°F (220°C) with a rack in the lower third.
- 2. Mix blueberries, sugar, cornstarch, lemon zest/juice, cinnamon, and salt; rest 10 minutes.
- 3. Spoon filling into crust; dot with 1 tbsp butter (optional).
- 4. Make streusel by rubbing cold butter into flour, brown sugar, oats, cinnamon, and salt; sprinkle evenly on top.
- 5. Bake 15 minutes at 425°F (220°C), then reduce to 375°F (190°C) and bake 45–55 minutes more.
- 6. Tent with foil if topping browns too fast; pie is done when filling bubbles thickly in the center.
- 7. Cool at least 2 hours before slicing (this sets the filling).
Why You’ll Love This Recipe
- Big, juicy blueberry flavor balanced with bright lemon and a whisper of cinnamon.
- Crisp oat-brown sugar streusel that caramelizes at the edges for a crunchy, buttery bite.
- Reliable thickening (no soupy slices) with clear “doneness” cues.
- Works with fresh or frozen blueberries, so you can bake it year-round.
Grocery List
- Produce: Blueberries (fresh or frozen), 1 lemon
- Dairy: Unsalted butter
- Pantry: All-purpose flour, granulated sugar, light or dark brown sugar, rolled oats, cornstarch, ground cinnamon, fine salt, vanilla extract (optional), coarse sugar (optional)
Full Ingredients
Flaky Pie Crust (Bottom Crust Only)
- 1 1/4 cups (150 g) all-purpose flour
- 1 tbsp (12 g) granulated sugar
- 1/2 tsp fine salt
- 1/2 cup (113 g) unsalted butter, cold and cut into 1/2-inch cubes
- 3–5 tbsp (45–75 ml) ice water
Blueberry Filling
- 6 cups (900 g) blueberries (fresh, or frozen and not thawed)
- 3/4 cup (150 g) granulated sugar
- 1/4 cup (32 g) cornstarch
- 1 tbsp finely grated lemon zest (from 1 lemon)
- 2 tbsp (30 ml) fresh lemon juice
- 1/2 tsp ground cinnamon
- 1/4 tsp fine salt
- 1 tsp vanilla extract (optional)
- 1 tbsp (14 g) unsalted butter, cut into small pieces (optional, for dotting)
Brown-Sugar Oat Streusel Topping
- 3/4 cup (90 g) all-purpose flour
- 1/2 cup (100 g) packed light or dark brown sugar
- 3/4 cup (75 g) rolled oats (old-fashioned)
- 1/2 tsp ground cinnamon
- 1/4 tsp fine salt
- 6 tbsp (85 g) unsalted butter, cold and cut into small cubes
- 1 tbsp (12 g) coarse sugar (optional, for extra sparkle and crunch)
Step-by-Step Instructions
Step 1: Make and chill the pie dough
In a large bowl, whisk together the flour, sugar, and salt. Add the cold butter cubes and cut them in using a pastry cutter or your fingertips until the mixture looks like coarse crumbs with some pea-size pieces of butter still visible.
Drizzle in 3 tablespoons (45 ml) ice water and toss with a fork. Add more ice water, 1 tablespoon (15 ml) at a time, just until the dough holds together when you squeeze it (avoid over-wetting).
Form the dough into a disk, wrap tightly, and refrigerate for at least 45 minutes (or up to 2 days).
Step 2: Roll out the crust and fit the pie plate
On a lightly floured surface, roll the chilled dough into a 12-inch round (about 1/8-inch thick). Transfer to a 9-inch pie dish, letting the dough settle into the corners without stretching.
Trim to a 1-inch overhang, fold under, and crimp as desired. Refrigerate the prepared crust for 15 minutes while you make the filling and topping. This helps keep the crust flaky and defined.
Step 3: Preheat the oven and set up for a crisp bottom
Place a rack in the lower third of the oven and preheat to 425°F (220°C). If you have a rimmed baking sheet, place it on the rack while the oven heats; baking the pie on a hot sheet helps the bottom crust start baking immediately.
Step 4: Mix the blueberry filling and let it macerate briefly
In a large bowl, gently combine the blueberries, granulated sugar, cornstarch, lemon zest, lemon juice, cinnamon, and salt (and vanilla, if using). Stir until the blueberries are evenly coated.
Let the mixture stand for 10 minutes. This draws out some juice and helps the cornstarch dissolve so it thickens smoothly in the oven.
Step 5: Make the brown-sugar oat streusel
In a medium bowl, mix the flour, brown sugar, oats, cinnamon, and salt. Add the cold butter cubes and work them in with your fingertips until the topping forms clumps ranging from sandy crumbs to dime-size nuggets.
For extra crunch, stir in the coarse sugar (optional). Keep the streusel in the refrigerator if your kitchen is warm.
Step 6: Assemble the pie
Spoon the blueberry filling into the chilled crust, scraping in any juices from the bowl. Spread into an even layer. Dot the top with 1 tablespoon (14 g) butter pieces if you like a slightly richer finish.
Sprinkle the streusel evenly over the fruit, making sure some larger clumps remain for that crisp, craggy topping. If any streusel falls onto the pie rim, brush it back onto the topping so the crust edge can brown cleanly.
Step 7: Bake until bubbling and caramelized
Set the pie on the preheated baking sheet (or a regular sheet pan to catch drips). Bake at 425°F (220°C) for 15 minutes.
Without removing the pie, reduce the oven temperature to 375°F (190°C) and continue baking for 45–55 minutes, until:
- the streusel is deep golden brown with darker caramelized edges, and
- the filling is bubbling thickly in the center (not just around the edges).
If the streusel starts getting too dark before the filling is fully bubbling, loosely tent the pie with foil for the final 10–20 minutes.
Step 8: Cool completely for clean slices
Transfer the pie to a wire rack. Cool for at least 2 hours before slicing (3 hours is even better). The filling thickens as it cools; cutting too soon will make it runny.
Slice and serve as-is, or with vanilla ice cream or lightly sweetened whipped cream.
Pro Tips
- Watch for center bubbles: The pie is properly thickened when you see slow, thick bubbles breaking through the center of the topping. Edge bubbling alone isn’t enough.
- Frozen berries work beautifully: Use them straight from the freezer (do not thaw). If your frozen berries are very icy, add 1 extra tablespoon (8 g) cornstarch.
- Keep the streusel cold: Cold butter in the topping creates crisp, distinct crumbles instead of a soft layer.
- Prevent a soggy bottom: Bake on the lower rack and use a preheated sheet pan. This helps the bottom crust set quickly.
- Shield the crust edge if needed: If the rim browns faster than the topping, cover just the crust edge with a pie shield or a strip of foil for the last 20–30 minutes.
Variations
- Almond-blueberry streusel: Add 1/4 tsp almond extract to the filling and replace 1/4 cup (25 g) of the oats with 1/4 cup (25 g) sliced almonds.
- Mixed berry streusel pie: Replace up to 2 cups (300 g) of blueberries with raspberries or blackberries. Keep the total fruit at 6 cups (900 g).
- Store-bought shortcut: Use 1 refrigerated or frozen 9-inch pie crust. Keep everything else the same; chill the crust in the pie plate for 15 minutes before filling.
Storage & Make-Ahead
Cool completely, then store the pie loosely covered at room temperature for up to 1 day. For longer storage, cover and refrigerate up to 4 days.
To re-crisp the streusel, warm slices on a baking sheet at 325°F (165°C) for 10–12 minutes (or until the topping feels crisp again). The baked pie also freezes well: wrap cooled pie tightly in plastic wrap and then foil; freeze up to 2 months. Thaw overnight in the refrigerator and rewarm at 325°F (165°C) for 20–30 minutes.
Make-ahead options: pie dough can be made and refrigerated up to 2 days (or frozen up to 2 months). Streusel can be mixed and refrigerated up to 3 days (keep it covered).
Nutrition (per serving)
Approximate, based on 8 servings: 430 calories, 18 g fat, 64 g carbohydrates, 4 g protein, 4 g fiber, 36 g sugar, 280 mg sodium.
