The easiest triple berry crumble, made with frozen berries! Topped with a delicious oat crumble topping and ready in just 10 minutes!

What Makes This Recipe Great

If you’re like me, you crave perfect spring berries all year long. Thanks to this frozen berry crumble dessert, I can enjoy fresh berry desserts any time! My freezer is always stocked with a huge back of frozen berries from Costco. Whether I decide to make a smoothie, this dessert, or anything else with berries, that frozen bag is my go-to!

The best part? Frozen berries aren’t just good frozen. Thaw them out, and you have yourself the perfect berries for whatever dish you plan to make!

This easy mixed frozen berries recipe comes together in just 10 minutes and features the yummiest oat crumble topping. A quick and easy dessert the whole family will love!

Watch The Recipe Video

Note: You can also watch this recipe video on YouTube

closeup of a bite of berry crumble with oat crumble topping

How to Make This Recipe

Frozen fruit is best because it is frozen when it is at peak freshness. It has tons more flavor and nutrients. Plus, frozen organic fruit is much cheaper than fresh. Win win!

Since the berries are getting baked, it is perfect to use frozen berries. They’re going to get all soft and mushy anyway. Even better? You can cook it with the berries frozen! No need to thaw them. You can have this frozen berry crumble prepped and in the oven in less than 10 minutes. Love that!

Ingredient Notes

ingredients to make a crumble dessert with frozen berries

Flour & Sugar: The berry filling comes together quite easily. Because the berries will sweat a bit, I like to thicken them with some added flour, along with a little granulated sugar for added sweetness. Some recipes use sugar and cornstarch, but I prefer flour!

Lemon Zest: Don’t miss this step! The lemon zest adds brightness to the berry mixture which is a must.

Frozen Berries: My favorite frozen berries to use are a combination of raspberries, blueberries, and blackberries. I love the fruit mixture, but you could use just 1 berry or any combination of other berries. For larger fruit/berries like strawberries, cherries, mango, etc I will pulse the frozen fruit in the food processor a few times so the chunks are more bite-size.

Fresh Berries: This same recipe also works for fresh fruit too! Just substitute the same amount of fresh berries for frozen. No other substitutions or changes in baking time are needed.

Oat Crumble Topping: The real star of this frozen berry crumble is the oat crumble topping. Crunchy and toasty rolled oats mixed with unsalted butter, flour, and brown sugar. It crisps up atop the berries and gives this dessert a perfect sweet oat crumble crunch. Literally, the best oat crumble topping I have ever had!

Recipe Step by Step

step by step photos making the triple berry crumble

  1. In a large bowl, make the berry filling by combining all ingredients and tossing to combine. Set aside.
  2. In a separate mixing bowl, make the oat crumble by combining all ingredients, then use your fingers to pinch the butter and incorporate it with the dry ingredients. Keep pinching and tossing together with your hands until evenly combined. You will be left with many pea-sized pieces of butter mixed in with the oat mixture. Set aside.
  3. Pour the berry filling into a 1-1/2 quart baking dish (or an 8×8 pyrex baking dish, a pie baking dish, or even a 12″ cast iron skillet). Top with the oat crumble topping and spread to an even layer.
  4. Bake uncovered until the berry filling is bubbling, and the oat crumble top is golden brown, about 1 hour. Let cool for 1 hour before serving.
  5. Serve at room temperature. Delicious with ice cream or whipped cream.
the easiest frozen berries dessert recipe: berry crumble with one scoop taken out

Expert Tips

How to Serve this Triple Berry Crumble: Top this frozen fruit crumble with some ice cream, and you’ve got the easiest and most amazing dessert to serve to guests or your family!

Make-Ahead: You can make this up to step 4, then cover tightly and refrigerate for up to 5 days or freeze for up to 6 months. Bake it thawed or fully frozen until golden and bubbling, about 1 hour.

Leftovers: Leftovers will keep in an airtight container refrigerated for at least 5 days. Heat up in the microwave and serve with vanilla ice cream.

a white plate with a piece of triple berry crumble and a scoop of vanilla ice cream with a black ice cream scooper in the background

FAQs

Can I make this berry crumble with just one type of frozen berry?

Yes! Sub in whatever berry you love. This frozen berry dessert recipe would work so well with frozen strawberries, raspberries, etc. So grab your favorite frozen berry and transform this recipe into Frozen Blackberry Crumble, Frozen Blueberry Crumble, and more! The instructions stay exactly the same regardless of the berries you choose!

Can I make this berry crumble recipe dairy-free?

I have not tried to do this myself, but the substitutions for a dairy-free berry crumble would be pretty easy. Simply swap out the butter in the oat crumble topping for vegan butter (I like Miyokos!), and serve with dairy-free vegan ice cream. Let me know in the comments how this turns out!

Can I freeze this frozen berry dessert and make it later?

Yes! Simply freeze leftovers in a freezer-safe, airtight container for up to 6 months. Thaw overnight in the refrigerator or go straight from frozen and bake at 350F until warmed and bubbly.

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frozen berry crumble topped with oat crumble topping and vanilla ice cream

Easy Triple Berry Crumble | with Frozen Berries!

The easiest triple berry crumble, made with frozen berries! Topped with a delicious oat crumble topping & ready in just 10 minutes!
5 from 620 ratings

Ingredients 
 

Berry Filling

  • 4 cups frozen mixed berries*, NOT thawed (about 24 ounces frozen fruit)
  • 3 tablespoons granulated sugar
  • 3 tablespoons all purpose flour
  • zest from 1 lemon
  • pinch of salt

Oat Crumble Topping

  • 1 cup old fashioned rolled oats
  • 1/2 cup brown sugar
  • 6 tablespoons all purpose flour
  • 1/2 cup butter, cut into small cubes

Instructions 

  • Preheat oven to 350 degrees with the oven in the middle position.
  • In a mixing bowl, make the berry filling by combining all ingredients and tossing to combine. Set aside.
  • In a separate mixing bowl, make the oat crumble by combining all ingredients, then use your fingers to pinch the butter and incorporate with the dry ingredients. Keep pinching and tossing together with your hands until evenly combined. You will be left with many pea sized pieces of butter mixed in with the oat mixture. Set aside.
  • Pour the berry filing into a 1-1/2 quart baking dish (or 8×8 pyrex baking dish, a pie baking dish, or even 12" cast iron skillet). Top with the oat crumble topping, and spread to an even layer.
  • Bake uncovered until the berry filling is bubbling, and the oat crumble is golden brown, about 1 hour. Let cool for 1 hour before serving. Serve room temperature. Delicious with ice cream or whipped cream.
  • See the Recipe Notes below for more tips, FAQ's and ingredient substitutions.

Notes

Frozen Berries: My favorite frozen berries to use are a combination of raspberries, blueberries and blackberries. But you could use just 1 berry, or any combination of other berries. For larger fruit/berries like strawberries, cherries, mango, etc I will pulse the frozen fruit in the food processor a few times so the chunks are more bite size.
Fresh Berries: This same recipe also works for fresh fruit too! Just substitute the same amount of fresh berries for frozen. No other substitutions or change in baking time are needed.
Make Ahead: You can make this up to step 4, then cover tightly and refrigerate for up to 5 days or freeze up to 6 months. Bake it thawed or fully frozen until golden and bubbling, about 1 hour.
Leftovers: Leftovers will keep in an airtight container refrigerated for at least 5 days, or frozen for at least 6 months. 
Calories: 378, Total Carbs: 56.5g, Protein: 3.8g, Fat: 15.7g, Fiber: 4g, Net Carbs: 53g
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