This Mixed Berry Pie with Oatmeal Crumb Topping recipe is a perfect combination of tart and sweet flavors. The juicy berry filling and buttery oatmeal crumb topping make it a crowd-pleaser, easy to make, and perfect for any occasion.
Triple Berry Pie
Mixed Berry Pie with Oatmeal Crumb Topping is a classic dessert that is loved by all. This delicious pie is filled with frozen berries, providing a balance of sweet and tart flavors in a juicy filling. The oatmeal streusel crumb topping is so buttery and adds a satisfying crunch. The pie is so good when served warm, topped with a big scoop of vanilla ice cream, and enjoyed with family and friends. Plus it’s always a hit at Thanksgiving, Christmas, or any holiday and celebration.
- Frozen mixed berries– Any variety of mixed berries will taste good in this pie. I used the Berry Medley variety with blackberries, blueberries, strawberries, and raspberries. No need to thaw it! You could also use fresh berries if you prefer.
- Oats– The key ingredient for the crumble topping. Old-Fashioned Oats are preferred for the best consistency but Minute Oats could be used as a substitute for finer more sandy texture.
- White granulated sugar– Add more or less for your desired sweetness for the filling.
- Brown sugar– White and brown sugar give the crumble topping the perfect sweetness.
- Cornstarch– It helps thicken up the filling of the pie.
- Lemon juice– This is important to help balance the sweetness of the berries and give them a slightly tart bite.
- Butter– For the crumble topping to bring together the sugar and oats. And just a little pat of butter rounds out the flavors of the filling and makes it incredibly moist.
- Pre-made or homemade pie crust
This pie is easy to make. All you have to do is:
- Prepare Pie Crust: Prepare a homemade crust or thaw a refrigerated pre-made crust and place in a deep dish pie pan.
- Make the pie filling: Boil the frozen berries with white sugar in a large saucepan. If you want the berries to be smaller, mash them with the back of a spoon against the saucepan. Once it comes to a light boil, mix the lemon juice and cornstarch together and then add it to the filling. Stir in the butter. It will start to thicken up as it cools down.
- Make the crumble topping: Mix oats, flour, white sugar, brown sugar, and salt in a medium bowl. Add in the softened butter and mix it all together. I recommend just digging in with clean hands so that the butter mixes in well. A little messy but totally worth it!
- Assemble and bake the pie: Pour the cooled berry mixture into the unbaked pie crust. Then crumble the topping over the entire top of the pie. Bake uncovered for 25 minutes on a baking pan. This pie has a tendency to bubble over so a baking pan underneath is really helpful! The crumble topping should be nicely crispy and golden brown. Then drape a piece of aluminum foil over the entire pie (don’t pinch the sides) and place back into the oven to cook for 25-35 more minutes until the crust has completely cooked. This keeps the top from over-browning.
- Cool and serve: Allow the pie to completely cool. This might take 3 or more hours. It’s tempting to cut into it but try to resist so that the filling will set up and not be runny. When it’s ready, get a big scoop of ice cream and enjoy!
If there are any leftovers, store Mixed Berry Pie covered in the refrigerator for up to 5 days or freeze for up to 3 months. To reheat, allow the pie to come to room temperature. Enjoy at room temperature or reheat in the microwave or oven until warm.
Frequently Asked Questions
The best way to keep the mixed berry pie from becoming runny is to allow the pie to fully cool after baking. This will help the filling to set up and thicken.
This Mixed Berry Pie is easily made with frozen berries. No need to thaw them before adding them to the saucepan to cook.
The crumb topping is added right before baking. Halfway through baking, cover lightly with a piece of aluminum foil to prevent the topping from burning.
More Delicious Desserts
Mixed Berry Pie with Oatmeal Crumb Topping
- 1 homemade or pre-made deep dish pie crust unbaked
- 7 cups frozen mixed berries
- 1 cup white granulated sugar
- 1/4 cup cornstarch
- 2 tablespoons lemon juice
- 2 tablespoons butter
Oatmeal Crumb Topping
- 1 cup all-purpose flour
- 1/2 cup old-fashioned oats
- 1/3 cup white granulated sugar
- 1/3 cup brown sugar
- 6 tablespoons butter softened
- 1/4 teaspoon salt
- Preheat oven to 400 degrees Fahrenheit. Prepare the pie crust in a deep dish pie pan and place on a baking sheet. Set aside.
- In a large saucepan, add frozen berries and white sugar and heat over medium-high heat until lightly boiling. Mix lemon juice and cornstarch together and pour into the berries. Stir and then remove from heat. Add the butter and stir until fully melted. The berry filling will thicken as it cools.
- In a medium bowl, stir together flour, oats, white sugar brown sugar, and salt. Add in the softened butter and mix with a fork or clean hands until the topping becomes crumbly. Pour the filling into the pie crust and add the crumble topping evenly over the entire top of the pie.
- Place the pie pan with the baking sheet into the oven and bake for 25 minutes until the topping becomes golden brown. Remove from the oven. Place a piece of aluminum foil over the entire pie without pinching the sides and return to the oven. Bake for an additional 25-35 minutes until the bottom of the crust has fully cooked.
- Remove from oven and allow to fully cool for around 3 or more hours before slicing. Enjoy!