Gluten Free Rhubarb Crumble

Like a gluten free strawberry rhubarb crumble, this gluten free rhubarb crumble relies on plenty of tart rhubarb to make a jammy filling that holds up a beautifully buttery gluten free topping. I'm such a fan of rhubarb, draping it over a gluten free rhubarb upside down cake, simmering it into rhubarb compote, or tucking it into gluten free rhubarb scones. This is yet another option to add to the dessert arsenal, and it's lovely on the 4th of July, or any night when rhubarb is in glorious season.

A note on the butter: Many recipe calls for using cold butter that's rubbed into the topping. I prefer to use melted butter, but don't worry. A brief stint in the fridge will solidify and chill the butter so that the topping will get nice and crumbly after it's baked. You'll just crumble up the chilled topping when you add it to the rhubarb rather than create a crumbly topping when adding the butter.

Why I Love This Easy Crumble

A crumble is such a great summer (or spring) dessert: It's quick to make, highlights seasonal produce, and oh yeah, is delicious! In my rhubarb crumble, the rhubarb is the star, and there's plenty of it, so you'll truly taste it. A simple topping made from gluten free flour, sugar, and butter adds a touch of sweetness to balance the tart rhubarb but doesn't overwhelm its unique flavor. Here's why I adore this crumble:

• Simply gluten free. All of the ingredients here are gluten-free, but you seriously won't be able to tell the difference between this gluten-free crumble and one that's made with all-purpose flour.
• Not too sweet. I hate a dessert that's so sweet that the sugar overpowers its actual taste. There's just enough sugar here to offset the natural tartness of the rhubarb while still letting the lightly floral, super special flavor of the rhubarb come through.
• Easy. No pre-cooking of the rhubarb and no real fuss is needed to throw this together, making it perfect for a last-minute dessert option or for a beginning baker to try.

Ingredients You'll Need

Make sure to scroll down to my recipe card at the bottom of this post for the full ingredient amounts and instructions.

• Gluten free flour - I always use my homemade gluten free flour blend, and you can use a 1:1 gluten free all purpose flour of choice.
• Baking powder - A little fresh baking powder gives the crumble lift. Make sure it's fresh before using it.
• Salt - I always use fine sea salt, and table salt works, too.
• Sugar - Brown sugar in the topping and granulated sugar in the filling add sweetness.
• Lemon - You'll need the zest and juice of 1 lemon.
• Butter - Unsalted butter is ideal, but you can use salted butter if needed. Just omit the added salt.
• Rhubarb - About 8 stalks of rhubarb (340 grams). Choose firm rhubarb with no brown spots.
• Strawberries - I used 1 quart of strawberries (450 grams).
• Arrowroot - This is used to help bind the filling. If you don't have arrowroot, cornstarch works well in a 1:1 substitution.

Variation Ideas

• Add berries - Up the ante by adding strawberries, raspberries, or blueberries.
• Try honey - Instead of sugar in the filling, swap an equal amount of honey.
• Nuts - Try 1 cup of sliced almonds or chopped pistachios added to the topping for some crunch and extra flavor.

What Makes this a Crumble?

Cobbler, crisp, crumble - what's the difference between them? Well, the topping is what makes each one its own unique dessert, though they are all fruit-based. A cobbler scatters a sweet, biscuity dough over fruit, while a crisp contains oats to make the topping, well, crisp. And in a crumble, like this rhubarb crumble, the topping is made from a mix of flour, sugar, and butter, with no oats needed.

Tips, Substitutions & Serving Suggestions

• Chill the topping - Even 15 minutes in the fridge will help the gluten-free flour hydrate and the butter firm up a little, which will make the topping even more tender and buttery after it's baked.
• Make topping in advance - Also consider making the topping in advance and freezing it in an airtight container for up to 2 months. Thaw the topping in the fridge before using.
• Other fruit - Use the topping recipe and general method with any kind of summer fruit you like, from cherries to peaches to plums to blackberries.
• Add vanilla - Stir in 1-2 teaspoons of pure vanilla extract or vanilla bean paste to the filling.
• Make it dairy-free - Use melted coconut oil or non-dairy butter instead of the butter.
• Serving options: With vanilla ice cream, lightly sweetened whipped cream, or a drizzle of caramel sauce!

Proper Storage & Reheating Options

• Counter - Leave the crumble in the pan and cover it with foil, then store it on the counter for up to 2 days.
• Fridge - Tightly cover the pan of crumble or transfer the crumble to an airtight container, then store it in the fridge for up to 5 days.
• To Reheat - Crumble rewarms great in the microwave for 30 seconds per portion, or pop the pan in a 350°F oven for about 10 minutes.