I’ve always thought fruit pies get better as summer turns to fall. There’s something about the way tart rhubarb and sweet blackberries come together that just works. My kids will eat berry pie any day of the week, but add that buttery walnut crumble on top? They’re asking for seconds before they’ve finished their first slice.
This pie hits that perfect spot between too sweet and too tart. The rhubarb brings a tangy bite while the blackberries add just enough sweetness to balance things out. And that crumble topping? It’s basically the best part. Forget a traditional top crust – this crunchy, cinnamon-spiced topping is where it’s at.
The best part is how easy it comes together. You don’t need to be a pastry expert or spend hours in the kitchen. Just slice, mix, crumble, and bake. Perfect for a weekend dessert or when you need to bring something to a potluck and actually want people to be impressed.
Why You’ll Love This Blackberry Rhubarb Pie
- Perfect balance of sweet and tart – The tangy rhubarb pairs beautifully with sweet blackberries, creating a flavor combination that’s not too sweet and totally addictive.
- Simple ingredients – You probably have most of these pantry staples on hand already, and the fresh fruit is easy to find during spring and summer.
- Impressive presentation – This pie looks like it came from a bakery, but it’s surprisingly easy to make at home, making it perfect for potlucks or family gatherings.
- Crunchy walnut topping – The buttery crumble with walnuts adds a nice texture contrast to the soft, juicy fruit filling.
- Ready in under 90 minutes – From start to finish, you can have this homemade pie on the table in about an hour and a half, which is pretty quick for a from-scratch dessert.
What Kind of Rhubarb Should I Use?
Fresh rhubarb is always your best bet for this pie, and you’ll find it in season during spring and early summer at most grocery stores and farmers markets. The color of the stalks doesn’t really matter for flavor – some rhubarb is bright red, some is more pink or green, and they all taste pretty similar, so just grab whatever looks fresh and firm. If you can’t find fresh rhubarb, frozen will work in a pinch, but make sure to thaw it completely and drain off any excess liquid before using it in your pie. Look for stalks that are crisp and firm, avoiding any that feel soft or look dried out at the ends.
Options for Substitutions
This pie is pretty forgiving when it comes to swapping ingredients:
- Blackberries: You can swap blackberries for raspberries, blueberries, or strawberries. Just keep the total amount of fruit the same – about 2 to 3 cups depending on your container size.
- Rhubarb: If rhubarb isn’t in season, you can use all berries instead. Just increase your berry amount to about 5 cups total and maybe add a tablespoon of lemon juice for that tart kick rhubarb provides.
- Walnuts: Not a fan of walnuts? Pecans or almonds work great in the crumble topping. You can also leave them out completely if you prefer a nut-free pie.
- Cornstarch: Tapioca starch or arrowroot powder work just as well for thickening the filling. Use the same amount and your pie will set up nicely.
- Butter: For the crumble topping, you can use cold coconut oil as a dairy-free option. Just make sure it’s solid and cold before mixing it with the flour and sugar.
- Pie crust: Store-bought works fine, but homemade is always nice if you have time. You can also skip the bottom crust entirely and make this as a crumble in a baking dish.
Watch Out for These Mistakes While Baking
The biggest mistake with rhubarb pie is not cutting the stalks into uniform pieces – aim for 1/2-inch chunks so they cook evenly and don’t leave you with some pieces that are mushy while others are still tough.
Another common issue is skipping the step of letting your fruit mixture sit for 10-15 minutes after combining it with the sugar and cornstarch, which helps draw out excess moisture and prevents a watery filling.
To avoid a soggy bottom crust, try blind baking your pie shell for 10 minutes before adding the filling, and make sure your crumble topping is cold when you add it to the pie – this creates a better texture and prevents it from melting into the fruit.
If your crumble starts browning too quickly during baking, simply tent the pie with aluminum foil for the last 20 minutes to protect the topping while the filling finishes cooking.
What to Serve With Blackberry Rhubarb Pie?
A big scoop of vanilla ice cream is pretty much required with this pie – the cold, creamy sweetness balances out the tart rhubarb perfectly. If you’re not an ice cream person, a dollop of fresh whipped cream or even some tangy Greek yogurt works great too. I like serving this pie slightly warm so the ice cream melts a little and creates a delicious sauce that mixes with all those berry juices. For a complete dessert spread, pair it with some hot coffee or cold milk, and you’ve got yourself a crowd-pleaser that works for any summer gathering or potluck.
Storage Instructions
Store: Once your pie has cooled completely, cover it loosely with foil or plastic wrap and keep it at room temperature for up to 2 days. If you want it to last longer, pop it in the fridge where it’ll stay good for about 4-5 days.
Freeze: This pie freezes really well if you want to make it ahead. Wrap it tightly in plastic wrap, then in foil, and freeze for up to 3 months. You can freeze it either baked or unbaked, whichever works better for your schedule.
Serve: If you’re serving from the fridge, let the pie sit at room temperature for about 30 minutes before slicing. For frozen pie, thaw it overnight in the fridge, then warm it in a 350°F oven for about 15-20 minutes if you want it warm and the topping crispy again.
| Preparation Time | 15-20 minutes |
| Cooking Time | 60-70 minutes |
| Total Time | 75-90 minutes |
| Level of Difficulty | Medium |
| Servings | 8 slices |
Estimated Nutrition
Estimated nutrition for the whole recipe (without optional ingredients):
- Calories: 2500-2700
- Protein: 25-30 g
- Fat: 120-130 g
- Carbohydrates: 340-360 g
Ingredients
For the base:
- 1 pie crust (I recommend Pillsbury for a consistent, flaky texture)
For the filling:
- 8 rhubarb stalks (cut into 1/2-inch thick slices)
- 16 oz blackberries
- 1 cup sugar
- 2 tbsp cornstarch
- 1/2 teaspoon vanilla extract
For the topping:
- 1/2 cup butter (I prefer Kerrygold for a richer crumble)
- 1/2 cup sugar
- 1 cup flour (I always use King Arthur all-purpose flour)
- 1/2 cup walnuts (coarsely chopped for a better crunch)
- 1/4 teaspoon ground cinnamon
Step 1: Prepare the Mise en Place and Preheat
- 8 rhubarb stalks
- 1/2 cup walnuts
- 1 cup flour
- 1 cup sugar
- 1/2 cup sugar
- 2 tbsp cornstarch
- 1/4 teaspoon ground cinnamon
Preheat your oven to 350°F.
While it heats, prepare your ingredients: cut the rhubarb stalks into 1/2-inch thick slices, coarsely chop the walnuts, and measure out all dry ingredients.
Having everything ready before assembly ensures smooth, efficient cooking and prevents ingredients from sitting too long after cutting.
Step 2: Make the Walnut Crumble Topping
- 1/2 cup butter
- 1/2 cup sugar
- 1 cup flour
- 1/2 cup walnuts, coarsely chopped
- 1/4 teaspoon ground cinnamon
In a bowl, combine the butter, 1/2 cup sugar, flour, coarsely chopped walnuts, and cinnamon.
Use a fork or your fingertips to work the butter into the dry ingredients until the mixture resembles coarse breadcrumbs with pea-sized pieces throughout.
I like to use Kerrygold butter here because its higher fat content creates a richer, more indulgent crumble texture.
Set the crumble mixture aside while you prepare the filling.
Step 3: Combine the Fruit Filling
- 8 rhubarb stalks, cut into 1/2-inch slices
- 16 oz blackberries
- 1 cup sugar
- 2 tbsp cornstarch
- 1/2 teaspoon vanilla extract
In a separate bowl, toss together the sliced rhubarb, blackberries, 1 cup sugar, cornstarch, and vanilla extract until the fruit is evenly coated and the cornstarch dissolves slightly from the fruit’s natural moisture.
This coating prevents a watery filling and helps thicken the juices as the pie bakes.
Let it sit for 1-2 minutes to allow the flavors to start melding.
Step 4: Assemble and Bake the Pie
- 1 pie crust
- fruit filling mixture from Step 3
- walnut crumble mixture from Step 2
Place the pie crust in a 9-inch pie dish (if not already in one).
Pour the fruit filling from Step 3 into the crust, spreading it evenly.
Distribute the crumble topping from Step 2 evenly over the filling, gently pressing it down slightly so it adheres but stays loose enough for crispness.
I like to leave some gaps in the topping so steam can escape during baking, which helps prevent a soggy crust.
Bake for 50-60 minutes until the crumble is golden brown and the fruit filling is bubbling around the edges.
Step 5: Cool and Serve
Remove the pie from the oven and let it cool on a wire rack for at least 20-30 minutes before slicing.
This resting time allows the filling to set slightly, making the pie easier to cut and serve.
The crust will also firm up as it cools, preventing it from becoming soggy.
Serve warm or at room temperature, optionally with vanilla ice cream or whipped cream.
Golden Blackberry Rhubarb Pie
Ingredients
For the base::
- 1 pie crust (I recommend Pillsbury for a consistent, flaky texture)
For the filling::
- 8 rhubarb stalks (cut into 1/2-inch thick slices)
- 16 oz blackberries
- 1 cup sugar
- 2 tbsp cornstarch
- 1/2 teaspoon vanilla extract
For the topping::
- 1/2 cup butter (I prefer Kerrygold for a richer crumble)
- 1/2 cup sugar
- 1 cup flour (I always use King Arthur all-purpose flour)
- 1/2 cup walnuts (coarsely chopped for a better crunch)
- 1/4 teaspoon ground cinnamon
Instructions
- Preheat your oven to 350°F. While it heats, prepare your ingredients: cut the rhubarb stalks into 1/2-inch thick slices, coarsely chop the walnuts, and measure out all dry ingredients. Having everything ready before assembly ensures smooth, efficient cooking and prevents ingredients from sitting too long after cutting.
- In a bowl, combine the butter, 1/2 cup sugar, flour, coarsely chopped walnuts, and cinnamon. Use a fork or your fingertips to work the butter into the dry ingredients until the mixture resembles coarse breadcrumbs with pea-sized pieces throughout. I like to use Kerrygold butter here because its higher fat content creates a richer, more indulgent crumble texture. Set the crumble mixture aside while you prepare the filling.
- In a separate bowl, toss together the sliced rhubarb, blackberries, 1 cup sugar, cornstarch, and vanilla extract until the fruit is evenly coated and the cornstarch dissolves slightly from the fruit's natural moisture. This coating prevents a watery filling and helps thicken the juices as the pie bakes. Let it sit for 1-2 minutes to allow the flavors to start melding.
- Place the pie crust in a 9-inch pie dish (if not already in one). Pour the fruit filling from Step 3 into the crust, spreading it evenly. Distribute the crumble topping from Step 2 evenly over the filling, gently pressing it down slightly so it adheres but stays loose enough for crispness. I like to leave some gaps in the topping so steam can escape during baking, which helps prevent a soggy crust. Bake for 50-60 minutes until the crumble is golden brown and the fruit filling is bubbling around the edges.
- Remove the pie from the oven and let it cool on a wire rack for at least 20-30 minutes before slicing. This resting time allows the filling to set slightly, making the pie easier to cut and serve. The crust will also firm up as it cools, preventing it from becoming soggy. Serve warm or at room temperature, optionally with vanilla ice cream or whipped cream.
