Quick Recipe Version (TL;DR)
Quick Ingredients
- 3 cups (360 g) sliced rhubarb, ¾-inch pieces
- 3 cups (450 g) sliced strawberries
- ⅔–¾ cup (130–150 g) granulated sugar
- 2 tbsp cornstarch
- 1 tbsp fresh lemon juice
- 1 tsp vanilla extract
- 1 cup (90 g) old-fashioned rolled oats
- ¾ cup (95 g) all-purpose flour
- ⅔ cup (135 g) packed light brown sugar
- ½ tsp ground cinnamon + pinch salt
- ½ cup (113 g) cold unsalted butter, cubed
- Optional: ⅓ cup (35 g) chopped nuts
- To serve: vanilla ice cream, lightly whipped cream, or pouring cream
Do This
- 1. Heat oven to 375°F (190°C). Butter a 2-quart baking dish (about 8-inch square or similar).
- 2. In a bowl, toss rhubarb, strawberries, sugar, cornstarch, lemon juice, vanilla, and a pinch of salt until evenly coated. Spread in the baking dish.
- 3. In another bowl, combine oats, flour, brown sugar, cinnamon, and salt. Cut in the cold butter with fingers or a pastry cutter until clumpy and crumbly. Stir in nuts if using.
- 4. Sprinkle the oat mixture evenly over the fruit, leaving some craggy peaks for extra crunch.
- 5. Bake 35–40 minutes, until the topping is deep golden-brown and the fruit is bubbling thickly around the edges.
- 6. Cool 10–15 minutes so the juices thicken slightly.
- 7. Serve warm with a generous scoop of vanilla ice cream or a drizzle of cold cream.
Why You’ll Love This Recipe
- Perfect balance of sweet strawberries and tart rhubarb, with bright, fresh flavor in every bite.
- Buttery, golden oat topping that bakes up crisp on top and delightfully chewy underneath.
- Simple pantry ingredients and straightforward steps, ideal for home cooks of any skill level.
- Flexible and forgiving: easy to tweak for sweetness, dietary needs, or the fruit you have on hand.
Grocery List
- Produce: Fresh rhubarb stalks, fresh strawberries, 1 lemon
- Dairy: Unsalted butter, heavy cream or whipping cream, vanilla ice cream (or your favorite ice cream)
- Pantry: Granulated sugar, light brown sugar, all-purpose flour, old-fashioned rolled oats, cornstarch, vanilla extract, ground cinnamon, kosher or sea salt, optional chopped nuts (pecans, walnuts, or almonds)
Full Ingredients
For the Strawberry–Rhubarb Filling
- 3 cups (360 g) fresh rhubarb, trimmed and sliced into ¾-inch pieces (about 4–5 medium stalks)
- 3 cups (450 g) fresh strawberries, hulled and sliced (halved or quartered, depending on size)
- ⅔–¾ cup (130–150 g) granulated sugar, to taste (use ¾ cup if your rhubarb is very tart)
- 2 tbsp (16 g) cornstarch
- 1 tbsp fresh lemon juice
- 1 tsp pure vanilla extract
- 1 pinch kosher or fine sea salt
For the Oat Crisp Topping
- 1 cup (90 g) old-fashioned rolled oats (not quick oats)
- ¾ cup (95 g) all-purpose flour
- ⅔ cup (135 g) packed light brown sugar
- ½ tsp ground cinnamon
- ¼ tsp kosher or fine sea salt
- ½ cup (113 g) unsalted butter, cold, cut into small cubes
- Optional: ⅓ cup (35 g) chopped pecans, walnuts, or sliced almonds
For Serving
- Vanilla ice cream, lightly sweetened whipped cream, or cold pouring cream
Step-by-Step Instructions
Step 1: Preheat the oven and prepare your baking dish
Preheat your oven to 375°F (190°C) with a rack in the middle position. This temperature allows the fruit to bubble and thicken while the topping turns golden and crisp.
Lightly butter a 2-quart baking dish, such as an 8-inch or 9-inch square pan or a similar oval gratin dish. Greasing the dish helps prevent sticking and makes serving easier, while also giving the edges of the fruit a nice, caramelized finish.
Step 2: Prep the strawberries and rhubarb
Rinse the rhubarb stalks under cool water and pat dry. Trim off and discard any leaves (they are not edible) and the very ends of the stalks. Slice the rhubarb into ¾-inch pieces so it cooks at the same rate as the strawberries.
Rinse the strawberries, dry them gently, hull to remove the green tops, and slice them. Large berries can be quartered; smaller ones can be halved. Aim for bite-sized pieces so every spoonful has a mix of fruit.
Step 3: Mix the bright, jammy fruit filling
In a large mixing bowl, combine the sliced rhubarb and strawberries. Sprinkle the granulated sugar and cornstarch evenly over the fruit. Add the lemon juice, vanilla, and a pinch of salt.
Toss everything together until the cornstarch is no longer visible and the fruit is evenly coated with a glossy, sugary mixture. The sugar will start drawing out some of the juices–this is good, as it will help create a thick, jammy sauce in the oven. Scrape the fruit mixture (and all the juices) into your prepared baking dish and spread it into an even layer.
Step 4: Make the buttery oat crisp topping
In a separate medium bowl, combine the oats, flour, brown sugar, cinnamon, and salt. Stir with a fork or whisk to break up any clumps of sugar and distribute the cinnamon evenly.
Add the cold, cubed butter to the dry ingredients. Using your fingertips, a pastry cutter, or two butter knives, work the butter into the mixture until it forms coarse crumbs with some larger, pea-sized pieces. These buttery clumps are what create the crisp, crunchy texture. If you are using nuts, gently fold them in now so they are distributed throughout the topping.
Step 5: Assemble the crisp
Crumble the oat topping evenly over the fruit mixture in the baking dish. Do not press it down firmly; you want loose, craggy bits and uneven mounds, which will brown beautifully and stay crisp. Make sure the fruit is mostly covered, but a few peeks of fruit around the edges are fine and even attractive.
Place the baking dish on a rimmed baking sheet lined with parchment paper or foil. This catches any bubbling juices that may spill over and makes cleanup much easier.
Step 6: Bake until bubbly and golden
Transfer the crisp (on its baking sheet) to the oven and bake for 35–40 minutes. The topping should be deep golden-brown and crisp to the touch, and the fruit should be bubbling thickly around the edges and possibly through a few small gaps in the topping.
If the topping is browning too quickly after about 25–30 minutes but the filling is not yet bubbling, tent the dish loosely with aluminum foil and continue baking until the fruit is done. When baked properly, the filling will look slightly thickened and glossy rather than watery.
Step 7: Cool briefly and serve warm
Remove the crisp from the oven and place it on a cooling rack. Let it rest for at least 10–15 minutes. This short cooling period allows the juices to thicken so each serving holds together better, while the crisp is still irresistibly warm.
Spoon the warm strawberry–rhubarb crisp into bowls, making sure everyone gets both plenty of jammy fruit and crunchy topping. Top with a scoop of vanilla ice cream, a dollop of softly whipped cream, or a splash of cold heavy cream. Serve immediately while the topping is still crisp and the fruit is warm and fragrant.
Pro Tips
- Adjust sweetness to your fruit: Very tart rhubarb or out-of-season strawberries may need the higher end of the sugar range (¾ cup). Very sweet, ripe strawberries may only need ⅔ cup.
- Keep the butter cold: For the crispiest topping, start with well-chilled butter and work quickly. If the kitchen is warm, you can chill the topping in the fridge for 10 minutes before baking.
- Use old-fashioned oats: Rolled old-fashioned oats give the best texture. Quick oats tend to get mushy, and steel-cut oats will stay too hard.
- Let it bubble: Do not pull the crisp out of the oven until the fruit is actively bubbling around the edges. This is a key sign that the cornstarch has thickened the juices properly.
- Double for a crowd: For a larger gathering, double the recipe and bake in a 9×13-inch dish. Add 5–10 minutes to the bake time as needed.
Variations
- Ginger–almond strawberry–rhubarb crisp: Add ½ tsp ground ginger to the fruit filling and ¼ tsp to the topping. Swap some or all of the nuts for sliced almonds and sprinkle a few extra on top before baking.
- Gluten-free version: Use certified gluten-free oats and substitute a 1:1 gluten-free all-purpose flour blend for the regular flour. The texture will still be wonderfully crisp and buttery.
- Mixed berry crisp: Replace up to half of the strawberries with fresh raspberries or blueberries. Keep the rhubarb amount the same for that signature tangy flavor.
Storage & Make-Ahead
Leftover strawberry–rhubarb crisp can be cooled completely, covered, and stored in the refrigerator for up to 3 days. Reheat individual portions in the microwave for 30–45 seconds, or rewarm the entire dish in a 325°F (165°C) oven for about 15 minutes to re-crisp the topping.
For make-ahead prep, you can assemble the oat topping up to 2 days in advance and store it in an airtight container in the refrigerator. You can also cut the rhubarb and hull the strawberries a few hours ahead and keep them chilled separately. Just before baking, toss the fruit with sugar, cornstarch, lemon, and vanilla, assemble the crisp, and bake as directed. This approach gives you freshly baked crisp with minimal last-minute work.
Nutrition (per serving)
Approximate values for 1 of 8 servings (without ice cream or cream): about 320 calories; 14 g fat; 8 g saturated fat; 47 g carbohydrates; 3 g fiber; 30 g sugars; 4 g protein; 170 mg sodium. Adding a scoop of vanilla ice cream will increase calories and sugars, but also adds extra satisfaction and that classic contrast of warm fruit and cold creaminess.
