This is the only thing I make when rhubarb season arrives: a simple, old-fashioned apple and rhubarb crumble that somehow manages to be both rustic and irresistible. I first put this combination together one spring when my market box was overflowing with bright stalks of rhubarb and a few tart Granny Smith apples. The contrast between the rhubarb's sharp tang and the apple's firmness creates a filling with texture and depth — not a mushy pile, but a pleasingly spoonable mix that still carries bite. The topping is intentionally clumpy and buttery so it soaks up some of the juices and caramelises at the edges.

I love how quick this comes together: about 15 minutes of active prep and less than 40 minutes in the oven. It’s the kind of dessert that turns a weekday into a celebration when the weather is warming and the kitchen begins to smell of bubbling fruit and toasted oats. We always serve it steaming with a generous scoop of vanilla ice cream; the contrast of hot and cold is part of the charm. Little moments like watching my kids excavate clumps of topping for the last bites make this a recurring favourite at our table.

Ingredients

• Rhubarb: Use about 4 1/2 cups of cleaned rhubarb stems, cut into 1 1/2-inch pieces (roughly one large bunch or 10–12 stems). Look for firm, brightly colored stalks; discard the leaves.
• Apples: 3 Granny Smith apples, peeled and cut into 1/2-inch cubes (about 3 cups once cut). Choose firm cooking apples that hold their shape rather than turning to mush.
• Sugar & citrus: 1/3 cup granulated sugar balances the rhubarb’s tang while the zest of one orange layers in a floral citrus note — optional but highly recommended.
• Oats & flour: 1 cup rolled oats and 1 cup all-purpose flour make the base of the topping; choose old-fashioned rolled oats, not quick oats, for better texture.
• Brown sugar & butter: 3/4 cup packed brown sugar plus 6 tablespoons melted unsalted butter provide caramel flavor and the clumpy texture when combined.
• Spices & lift: 1/2 teaspoon cinnamon and 1/2 teaspoon baking powder add warmth and a touch of lift to the topping; finish with a pinch of salt.
• To serve: Vanilla ice cream or warm pouring custard — we always recommend ice cream for the contrast between hot and cold.

Instructions

Preheat: Set the oven to 375°F (190°C). Position a rack in the center so the topping browns evenly while the fruit simmers underneath. Grease a 12 x 8-inch (30 x 20 cm) baking dish lightly with butter or nonstick spray. Prepare the filling: In a large mixing bowl toss the rhubarb pieces, peeled and cubed apples, 1/3 cup granulated sugar and the zest of one orange. Mix gently until the fruit is coated — the sugar will begin to draw out juice, which concentrates while baking and keeps the filling saucy but not soupy. Assemble the fruit layer: Spread the fruit evenly into the prepared 12 x 8-inch dish so the layer is about 1 to 1 1/2 inches deep. If your pan is smaller, use a slightly smaller dish so the fruit stays thick and juicy; if it’s much larger, the filling becomes thin and dries out. Make the topping: Combine 1 cup rolled oats, 1 cup all-purpose flour, 3/4 cup packed brown sugar, 1/2 tsp baking powder, 1/2 tsp cinnamon and a pinch of salt in a bowl. Pour in 6 tablespoons melted butter and mix with a wooden spoon using a cutting/smearing motion to incorporate the flour until the mixture looks sandy but starts to hold together when pressed. Scrunch & top: Grab handfuls of the topping and squeeze into fists to form clumps, then break them into rough chunks and scatter over the fruit so there are clusters rather than a uniform sand layer. These clumps absorb juices in a pleasing way without turning the fruit into a paste. Bake: Bake at 375°F (190°C) for about 35 minutes or until the rhubarb is tender when pierced with a knife and the topping is golden brown. Tougher, thicker rhubarb may need up to 45 minutes — check at the 35-minute mark and extend if needed. Rest & serve: Remove from oven and rest 5 minutes to let the juices settle. Serve warm with scoops of vanilla ice cream or a drizzle of warm custard for classic comfort.

Storage Tips

Store any leftovers loosely covered in the refrigerator for up to 2 days. Use an airtight container to prevent the crumble from absorbing other fridge odors. When reheating, place a portion in a small ovenproof dish and warm at 325°F (160°C) for 10–12 minutes to crisp the topping back up; avoid microwaving for long stretches as this makes the topping soggy. This dish is best eaten fresh and is not recommended for freezing because the topping will lose its desirable clumpy texture when defrosted.

Ingredient Substitutions

If you can't find rhubarb, substitute half a pound of tart berries like raspberries or a mix of strawberries and raspberries, but reduce sugar slightly. For the apples, Braeburn or Honeycrisp work well if you prefer a sweeter profile — reduce granulated sugar by 2 tablespoons if using sweeter apples. To make this dairy-free, use a vegan butter substitute or coconut oil for the topping and serve with dairy-free vanilla ice cream. For gluten-free versions, use a 1:1 gluten-free flour blend and certified gluten-free oats.

Serving Suggestions

Serve warm directly from the dish in generous bowls with a melting scoop of high-quality vanilla ice cream or a ladle of warm pouring custard. For a grown-up touch, drizzle a teaspoon of cold-brew coffee reduction or a tablespoon of bourbon over the warm crumble before adding ice cream. Garnish with finely grated orange zest for brightness or a sprinkle of toasted sliced almonds for extra crunch. Pair with strong tea or a glass of dessert wine for an evening dessert.

Cultural Background

Crumble is a versatile British dessert that gained popularity during food rationing in the 1940s because it used less butter than a traditional pie crust but delivered the same comforting fruit-and-crumb combination. Rhubarb has long been cultivated in northern Europe and the U.K., and pairing it with apple is a classic way to balance rhubarb’s tartness. This simple, homey dessert speaks to a tradition of resourcefulness and seasonal cooking — relying on whatever fruit is ripe in the garden or market.

Seasonal Adaptations

In spring, emphasise rhubarb with a splash of orange zest as in this version. Summer versions can shift to stone fruits like peaches and plums with a lemon zest swap, and autumn crumbles favour spiced pears with a pinch more cinnamon and nutmeg. For winter holidays, add 1/4 cup chopped crystallized ginger and replace the orange zest with 1/2 teaspoon ground ginger for warmth. Adjust sugar and baking time slightly depending on the juiciness of the fruit you use.

Meal Prep Tips

For easy entertaining, prepare the fruit mixture a day ahead and keep chilled in the fridge. Mix the dry topping ingredients in advance and store in an airtight container; add melted butter and form clumps just before baking. If assembling fully ahead of time, cover the assembled dish tightly and store for up to 12 hours, then add 5–10 extra minutes to the bake time as the chilled filling will take slightly longer to bubble. Use shallow, individual ramekins for portable single servings if you want to deliver to friends or freeze individual portions for quick reheating.

This apple and rhubarb crumble is a humble, forgiving dessert that celebrates seasonal produce and simple techniques. Whether you serve it at a casual family dinner or bring it to a neighbour’s house, it’s the kind of food that creates small moments of joy. Make it your own by adjusting fruit ratios, spices or accompaniments, but please don’t skip the ice cream — it’s non-negotiable in our home.