Dive into the delightful simplicity of making a Strawberry Rhubarb Crisp, a perfect blend of tangy rhubarb and sweet strawberries topped with a golden, crunchy oat crust. Learn to make a classic fruit crisp that is adaptable to any season or fruit and is easy to modify for various dietary needs.

If you’ve been following Bunsen Burner Bakery for any length of time, you know I’m a big fan of rhubarb desserts. I’m not entirely sure why – maybe it’s because the growing season is so short here in the mid-Atlantic, or because seeing rhubarb show up at the farmer’s market means we’ve made it to spring and fresh summer produce is right around the corner. Either way, it’s not spring in our household without at least one (or two!) fresh rhubarb desserts.

This year, I’m combining my love of rhubarb with a strange gap in my collection of recipes: a crisp! After a friend asked for a good crisp recipe, I realized I’ve never shared one, so let’s start with this Strawberry Rhubarb Crisp (and don’t worry, if you don’t have rhubarb, you can easily sub in other fruit or berries!). Fruit crisps are a perfect summer dessert and I make them all the time in summer – I just haven’t waited long enough to photograph them before eating!

Crisps are extremely easy to make and incredibly versatile. They require minimal preparations – often just chopping some fruit and mixing a quick topping. There is no need to roll out pastry dough, as required for pies, or even to let the dessert cool first before slicing, like pie bars. Digging into a still-warm crisp with a spoon is pure fruit dessert perfection!

Plus, they’re easily adaptable to gluten-free, dairy-free, and are naturally egg-free, so it’s a perfect choice if you’re baking for someone with a food intolerance. See? Crisps really are the perfect summer dessert!

Ingredients and Substitutions

Let’s start with a breakdown of the ingredients needed for our Strawberry Rhubarb Crisp, along with some easy substitutions based on what you may have available or dietary restrictions.

• Fruit: We’re strawberries and rhubarb, but you can swap this out for other fruits, such as blueberries, raspberries, cherries, or peaches. While I usually use fresh fruit during summer, you can make this crisp any time of year using frozen fruit – allow any frozen strawberries to thaw a bit first for easier slicing.
• Granulated Sugar
• Cornstarch: Cornstarch serves as the thickening agent for the filling. As the crisp heats, cornstarch swells and forms a gel, thickening the juices released by the fruit.
• Vanilla Extract
• Oats: Use old-fashioned rolled oats for the best flavor and texture. Quick-cooking oats result in a softer topping, rather than a crunchy contrast to the cooked fruit.
• Flour: Any sort of flour will work here – use a gluten-free flour blend or even ground almond flour as a substitute.
• Brown Sugar: If you don’t have brown sugar on hand, you can also use granulated sugar for the crisp topping, but brown sugar provides an extra depth of flavor that pairs so well with the crisp.
• Cinnamon: Cinnamon is a great starting point, but add your own favorite spices that pair well with your fruit – cardamom, ginger, or nutmeg are all delicious!
• Salt
• Butter: Butter is standard for the crispy topping, but melted coconut oil works just as well to keep the recipe dairy-free.

Step by Step Instructions

1. Preheat and Prep: Start by heating your oven to 350F. This temperature allows the filling to bubble, creating a gel between the cornstarch and the fruit juices, without burning.
2. Mix the Filling: In a large mixing bowl, toss together the fruit, sugar, cornstarch, and vanilla. Make sure all the fruit is well coated to help the cornstarch thicken the filling as it bakes.

3. Combine the Crisp Topping: In another bowl, mix the oats, flour, sugar, cinnamon, and salt. Drizzle in the melted butter and stir until you have coarse crumbs.

4. Assemble the Crisp: Pour the fruit mixture into the skillet and evenly sprinkle the topping over the fruit.

5. Bake: Place the skillet in the oven and bake for around 45 minutes, until you can see and hear the filling bubbling up around the crisp topping.

6. Serve: Let the crisp cool for a few minutes after removing it from the oven before serving warm or at room temperature. Optional but recommended: topping with a scoop of vanilla ice cream or a dollop of whipped cream!

Bake in a Cast Iron Skillet

While you can bake this in a metal, glass, or ceramic baking dish, I always recommend baking a crisp in a cast iron skillet. Cast iron maintains heat perfectly, which helps cook the topping evenly without overcooking the fruit underneath. You know I can’t write a post without working in a little science, so let’s learn a little about why cast iron distributes heat so well!

Kitchen Chemistry

Cast iron has a high heat capacity, meaning it can absorb a lot of heat before it becomes hot. This allows a cast iron skillet to absorb heat steadily and distribute it evenly across its entire surface, minimizing hot spots that are common in thinner, less dense materials. This slow and steady conduction is beneficial for cooking and baking process that require gentle, even heat, like this fruit crisp.

As another bonus, you can even store leftovers in the skillet in the refrigerator. Unlike ceramic or glass, a cast iron skillet can handle drastic temperature changes because it heats up and cools down slowly. Cast iron can go straight from the fridge into the oven., warming the crisp evenly and adding crunch back to the topping.

Recommended Tools

• Mixing Bowls: This set of glass mixing bowls is perfect for mixing the filling and the oatmeal crisp topping.
• Cast Iron Skillet: A 10-inch cast iron skillet is perfect for baking the strawberry rhubarb crisp.
• Chef Knife: Use a sharp knife to chop the rhubarb and strawberries.
• Ice Cream Scoop (optional): Perfect for serving the crisp with scoops of ice cream!

Tips and Tricks for the Best Strawberry Rhubarb Crisp

1. Adjust the Sugar: Rhubarb can be quite tart. If you prefer a sweeter dessert, consider adding an extra tablespoon of sugar to the filling or drizzle a bit of honey over the fruit before adding the topping. Inversely, if you are swapping the rhubarb for other berries, consider reducing the sugar amount by a tablespoon.
2. Fruit Variations: Don’t hesitate to mix up the fruits based on what is in season. Peaches, cherries, or blueberries make excellent additions or substitutions.
3. Spice it Up: Incorporate spices into the fruit mixture or topping. Cardamom, nutmeg, or allspice can complement cinnamon and add dept to the flavor profile.
4. Add Crunch: Adding chopped nuts, like almonds, walnuts or pecans, into the topping mixture adds a great extra crunch.
5. Serving Suggestions: Serve warm with a scoop of vanilla extract or a dollop of whipped cream.
6. Storage and Reheating: Store any leftovers covered in the refrigerator. Reheat in a warm oven to bring back some of the original crispy topping texture before serving.

More Rhubarb Recipes

• Almond Rhubarb Cake
• Blueberry Rhubarb Pie
• Chiplotle Rhubarb BBQ Sauce
• Cinnamon Streusel Rhubarb Bread
• Strawberry Rhubarb Oatmeal Bars
• Rhubarb Simple Syrup