Name: Mixed Berry Crisp with Oat Topping
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Yield: 6 servings
Cuisine: American
Ingredients: 3 cups mixed berries (blueberries, raspberries, strawberries, blackberries); ½ cup granulated sugar; 2 tablespoons cornstarch; 1 tablespoon lemon juice; 1 cup old-fashioned rolled oats; ½ cup all-purpose flour; ½ cup light brown sugar, packed; ½ teaspoon ground cinnamon; ¼ teaspoon salt; ½ cup unsalted butter, melted

Let Me Tell You About This Berry Crisp (and Maybe a Little More)

Okay, real talk—if there’s one thing that gets me excited about summer (besides not having to wear socks), it’s the excuse to make way too many berry desserts. This Mixed Berry Crisp with Oat Topping is one I come back to every year. Actually, I think the first time I made it was after picking buckets of wild blackberries with my cousin out by the old railway tracks—ended up with more scratches than berries, but still, it was totally worth it. These days, I just grab whatever berries look good at the store (or, erm, whatever’s on sale), but the recipe tastes like summer no matter what.

Oh, and if you’re wondering: yes, I’ve eaten this for breakfast. No regrets.

Why You'll Love This (Or At Least Why I Do)

I make this when I want something cozy but not fussy—like, if I’ve already dirtied half the kitchen and just want dessert to be easy. My family goes absolutely bonkers for this because it’s tangy, sweet, and not too heavy (even my brother, who claims not to have a sweet tooth, always sneaks seconds). Plus, you can use whatever berries you have—if I’m honest, I usually do; one time I threw in a handful of frozen cherries, and people thought I was a genius. Only takes about 15 minutes of prep, unless you get distracted by a podcast like I do, in which case, well, who’s counting?

What You’ll Need (and Some Swaps That Actually Work)

About 4 cups mixed berries (fresh, frozen, or even a combo—raspberries, blackberries, blueberries, strawberries, whatever’s rolling around in the fridge; I sometimes use frozen if I can’t be bothered to go shopping)
¾ cup white sugar (I swap in half brown sugar sometimes for a bit of a caramel vibe)
2 tablespoon cornstarch (if you’re out, plain flour works fine, or arrowroot powder—though it’s a bit fancy for my pantry)
1 tablespoon lemon juice (optional but I like the zing; bottled stuff is okay, don’t stress)
½ teaspoon vanilla extract (my grandmother insisted on Nielsen-Massey, but honestly, whatever you have is good)
1 cup rolled oats (quick oats in a pinch, but they’re a little mushier)
½ cup all-purpose flour
½ cup brown sugar (sometimes I just mix white and brown because that’s what’s in the jar)
½ cup (1 stick) unsalted butter, cold and cubed (you can use margarine, but I think it’s not quite as rich)
Pinch of salt
Optional: ½ teaspoon cinnamon or nutmeg (I always add cinnamon, but that’s just me!)

How To Make Mixed Berry Crisp With Oat Topping (No Fuss, Promise)

Preheat your oven to 180°C (that’s about 350°F). If you forget, like I do half the time, just pop everything in when it’s hot enough—crisp is forgiving.
In a big-ish bowl, gently toss your berries with the sugar, cornstarch, lemon juice, and vanilla. It’ll look a bit gloopy and odd—don’t panic, it sorts itself out in the oven. This is where I usually sneak a berry (for quality control, obviously).
Pour the berry mixture into a greased baking dish (anywhere from 8-inch square to 9x13 if you want to double it for a crowd). No need to be precious about it—just get it in.
For the oat topping: Mix your oats, flour, brown sugar, salt, and cinnamon in a separate bowl. Then add those cold butter cubes. I use my fingers to squish them in—less washing up than a pastry blender, but if you have one, go for it! You want it crumbly and a bit lumpy.
Scatter the topping all over the berries. Don’t worry if it’s uneven—more crispy bits later.
Bake for 35 to 45 minutes. It should be bubbly and golden on top. Sometimes my oven runs hot, so I check at 35 minutes. If it’s still pale, give it a few more minutes. If the edges look a bit dark, that’s fine, just means more caramelized bits (the best part, actually).
Let it cool for at least 10 minutes before scooping. Or not. I usually burn my tongue because I can’t wait.

Notes from a Messy Kitchen

If you use frozen berries, don’t bother thawing—but toss in an extra teaspoon of cornstarch, otherwise it’s a bit soupy.
Sometimes I skip the lemon juice if I don’t have any, and honestly, it’s still delish.
Oh, and don’t try to get the topping perfectly even—it’s more rustic (and easier) if it’s a bit haphazard.

Variations I’ve Tried (Some Winners, Some Not)

Once I swapped half the berries for diced apples—surprisingly great! Pears work too, but I found them a bit too soft for my taste (maybe I overbaked it?).
Nuts in the topping are fab—walnuts, pecans, or even sunflower seeds for crunch. The time I tried coconut flakes, though, it got a bit weirdly chewy. Maybe that’s just me.
If you want gluten-free, just use a GF flour blend and oats (check they’re certified gluten-free!). Tastes pretty much the same, promise.

Equipment (And How I Make Do Without)

A good-sized baking dish (anything oven safe, really; I once used a cast iron pan and it worked a treat)
Mixing bowls (or a big soup pot in a pinch—done that more than once)
Pastry blender or just your hands—fork works too, but it’s a bit slower

How To Store Your Crisp (If You Have Any Left!)

This keeps in the fridge for about three days, covered. You can reheat it in the oven or just have it cold (which is, oddly, really good for breakfast). Though honestly, in my house it never lasts more than a day!

How I Like To Serve It (And a Family Quirk)

A big scoop with vanilla ice cream is classic, but sometimes we do Greek yogurt if it’s morning. My dad swears by pouring a little cream over the top—says it’s “proper.” I can’t say I disagree (much as I tease him for being old school).

What I’ve Learned (A Few Small ‘Aha’ Moments)

Don’t rush the butter-in-the-topping step. I once tried melting it to save time and got a weird cake layer instead of crumbs. Oops.
Taste your berries—if they’re super tart, add a bit more sugar. If they’re sweet and juicy, you can cut back.
And actually, I find it works better if you let it sit for at least 15 minutes after baking—otherwise the filling’s runny. (Not that I always wait, but still...)

People Ask Me… (And Here’s What I Say)

Can I use only one kind of berry? Totally. All blueberries works great, or all strawberries, especially when they’re in season. Just maybe cut really big berries in half.
How do I make it less sweet? Easy, just reduce the sugar by about a quarter. Or serve it with tangy yogurt (I do that sometimes if I overdo the sugar by accident…)
Is it okay to prep ahead? Sort of! You can make the topping a day in advance, but the fruit gets a bit mushy if you let it sit too long. I usually assemble just before baking. But honestly, I’ve thrown it together in the morning and baked it after dinner; it was fine.
Can I freeze it? I’ve tried freezing leftovers (rarely have any), and it’s… okay. Not as crisp when reheated, but still tasty. If you want, check out this guide on freezing fruit crisps—pretty helpful.
Do I have to use butter? No, you can use coconut oil or even vegan butter. The flavor’s a bit different, but it works. I’ve done it for a dairy-free friend and nobody complained.
Any tips for making it fancy? Well, you could add orange zest or swap vanilla for almond extract. Or serve it in little ramekins for individual portions—looks posh, but honestly, it’s just for show. If you want ideas for making it gluten-free and a bit fancier, Cookie and Kate have a great recipe.

And that’s it! If you try this Mixed Berry Crisp with Oat Topping, let me know how it goes (or if you discover a new hack—especially one that doesn’t involve extra washing up). Sometimes I think I enjoy chatting about desserts almost as much as eating them. Almost.

Mixed Berry Crisp with Oat Topping