There’s something wonderfully nostalgic about a good crumb cake—and when rhubarb is involved, it takes that coziness to the next level. This Gluten Free Rhubarb Crumb Cake is the kind of bake that celebrates the brightness of spring, the comfort of homemade treats, and the joy of sharing something special with loved ones.

The tart, slightly tangy bite of fresh rhubarb pairs beautifully with a soft, tender cake and that buttery, golden crumble on top. Whether you’re gluten-free by necessity or simply experimenting, you won’t feel like you’re missing out. The flavor and texture of this cake are so satisfying, you might even forget it’s gluten-free!

Perfect for weekend brunches, afternoon coffee breaks, or gifting to a neighbor, this cake is simple to make and hard to resist.

Bold tip: This is the kind of cake that converts even the skeptics—non-gluten-free eaters will be going back for seconds!

What Makes This Crumb Cake Gluten Free?

Gluten-free baking isn’t just about removing wheat—it’s about creating a balanced blend that mimics the structure and texture of traditional flour. For this recipe, the base usually includes a gluten-free all-purpose flour blend, often made with a mix of rice flour, tapioca starch, and potato starch. Look for one that contains xanthan gum (or add it separately) to help the cake hold together.

If your topping includes oats, make sure they’re certified gluten-free. While oats are naturally gluten-free, they’re often processed in facilities that handle wheat, which can lead to cross-contamination—especially important for people with celiac disease.

To make this cake truly safe for everyone, pay attention to cross-contamination in your kitchen. Use clean tools, pans, and bowls that haven’t come into contact with gluten. Even wooden spoons or baking sheets can carry trace amounts.

Pro tip: Always double-check your ingredients, especially baking powder and vanilla extract, to ensure they’re gluten-free.

Star Ingredient: Fresh Rhubarb

If you’ve never baked with rhubarb, get ready for a sweet-tart surprise. Rhubarb looks a little like red celery, but its flavor is uniquely tangy—especially when baked. It softens beautifully in the oven and adds brightness that balances the richness of the cake and crumble topping.

Rhubarb is typically in season from late spring to early summer, making it a great choice for warm-weather baking. When shopping, look for firm, crisp stalks with vibrant red or pink coloring. The deeper the color, the more tart and flavorful they tend to be.

Store rhubarb in the fridge, wrapped in a paper towel and placed inside a plastic bag. It’ll stay fresh for about a week. And yes—you can use frozen rhubarb! Just thaw it first and drain any excess liquid to avoid a soggy cake.

Reminder: Only the stalks are edible—the leaves are toxic and should be discarded.

Let’s Talk Texture: The Perfect Crumb Topping

The crowning glory of this cake is its crumb topping—golden, buttery, and just the right amount of crunch. The magic lies in the ratio of fat to flour to sugar. Too much butter? It melts flat. Too little? It turns sandy.

The key is to chill your crumble topping before sprinkling it over the batter. This helps the crumbles hold their shape and bake into perfect clusters. Use cold butter, cut into the dry ingredients with a fork or pastry blender until you get pebble-sized chunks.

Want to add a personal twist? Try a pinch of cinnamon, some chopped pecans or walnuts, or even certified gluten-free oats for extra texture. These little touches add flavor depth and crunch that make the topping unforgettable.

Bold tip: Don’t overmix the crumble—you want chunks, not dust!

Essential Ingredients You’ll Need

Let’s break down the basics:

Gluten-free flour blend – Preferably one that contains xanthan gum
Fresh rhubarb – Washed, trimmed, and diced
Butter – Regular or dairy-free alternative
Sugar – White for sweetness, brown for depth in the crumble
Eggs – For structure and moisture
Milk or plant milk – Choose what works for your diet
Baking powder & salt – The leavening agents that make it rise
Vanilla extract – For that bakery-style aroma

For allergy-friendly adjustments, you can use vegan butter, coconut sugar, or even almond milk. Just be sure to use room temperature ingredients—they mix more evenly and help the cake rise properly.

Pro tip: If using a plant-based milk, make sure it’s unsweetened to control sugar levels in the cake.

Baking Tips for the Best Gluten Free Cake Texture

Gluten-free cakes can be tricky—they’re prone to being gummy or dry if not handled right. To get a tender, moist crumb:

Don’t overmix the batter. Stir just until combined to avoid a dense texture.
Let it rest before baking—10–15 minutes allows the flour blend to hydrate fully.
Use the right pan: an 8×8″ square or 9″ round cake pan works great. Line it with parchment or grease it well to avoid sticking.

To check for doneness, insert a toothpick into the center—it should come out with a few moist crumbs, not wet batter. If it’s browning too fast, tent with foil halfway through.

Bold tip: Every oven is different—start checking your cake 5 minutes before the timer says it’s done!

Easy Variations to Try

One of the best parts about this recipe? It’s totally flexible. You can tweak it to match the seasons, your cravings, or even dietary needs.

Add strawberries for a classic rhubarb-strawberry twist—just chop them small and toss with the rhubarb before folding into the batter. The sweetness of the berries balances rhubarb’s tartness beautifully.

Want to keep it dairy-free? Swap the butter for a plant-based version and use almond milk or oat milk instead of regular milk. It bakes up just as golden and tender.

If you’re into citrusy notes, a little lemon zest or a splash of vanilla extract can brighten the flavor and give the cake more depth. It’s especially nice if you’re serving it chilled.

Hosting brunch or planning gifts? Turn this batter into muffins or mini loaves. Just adjust the baking time—muffins bake faster (around 20–25 minutes), so keep an eye on them!

Bold tip: Dust the top with cinnamon sugar for a sweet crusted finish!

How to Serve It

This rhubarb crumb cake is lovely all on its own, but if you want to dress it up a bit, here are some ideas to make it shine.

Serve it warm with a dollop of whipped cream or a spoonful of thick Greek yogurt. That creamy contrast plays so well with the crumbly topping and tart rhubarb.

Enjoying it cold? Pair it with a hot cup of tea or rich coffee for a cozy snack or a weekend breakfast treat.

And for dessert, you really can’t go wrong with a scoop of vanilla bean ice cream. The contrast of hot and cold is divine.

Pro tip: Right before serving, sprinkle a little powdered sugar on top for that bakery-style finish. It looks elegant and adds just a hint of extra sweetness.

Make Ahead Tips & How to Store It

Planning ahead? You’re in luck—this cake stores well and keeps its texture beautifully.

Once baked and fully cooled, you can leave it at room temperature for 2–3 days, covered loosely with foil or a cake dome. If you want it to last longer, store it in the fridge, where it’ll stay fresh for about 5 days.

Want to freeze it? Totally doable! Wrap individual slices or the whole cake tightly in plastic wrap and then foil, or use a freezer-safe container. It’ll keep in the freezer for up to 2 months. To thaw, let it sit at room temp (unwrapped) or warm gently in the oven.

When it comes to reheating, skip the microwave—it can make the crumb soggy. Instead, warm slices in a 300°F (150°C) oven for 10–15 minutes to bring back that fresh-baked texture.

Bold tip: Store the crumble topping separately and re-toast it in the oven before topping if you want max crispiness.

Health Benefits of Rhubarb (and Going Gluten-Free)

Rhubarb isn’t just delicious—it’s also packed with health perks. It’s rich in fiber, vitamin K, and antioxidants, making it a great ingredient to sneak into desserts. That vibrant red color? It’s thanks to anthocyanins, which help fight inflammation and free radicals.

As for going gluten-free, this cake is a win for those with celiac disease or gluten intolerance. Using certified gluten-free flours ensures it’s safe and gut-friendly. Even if you’re not gluten-sensitive, reducing gluten now and then can give your digestion a break.

And if you’re using almond flour or coconut sugar in your swaps, you’ll also benefit from healthy fats, lower glycemic index, and added nutrients.

Bonus: This recipe can be adapted to be lower in refined sugar and dairy-free—perfect for clean baking without sacrificing flavor.

Troubleshooting Guide: Common Issues & Fixes

Even the best bakers run into issues—here’s how to fix the most common ones with this crumb cake:

Cake too wet or gooey in the middle? It could be due to too much rhubarb or underbaking. Rhubarb releases moisture as it cooks, so measure carefully and drain thawed frozen rhubarb.

Crumb topping disappeared or sunk into the cake? Your butter may have been too soft, or the topping was overmixed. Use chilled butter and crumble it gently—don’t press it down into the batter.

Cake falling apart when sliced? Let it cool completely before cutting. Gluten-free cakes need extra time to set up, and slicing too soon can cause crumbling.

Pro tip: Use an offset spatula or serrated knife for clean cuts, especially if serving at room temp.

FAQs

Can I use frozen rhubarb instead of fresh?
Yes! Just be sure to thaw and drain it thoroughly to remove excess moisture. Otherwise, it can make the cake soggy.

What gluten-free flour is best for crumb cakes?
A 1:1 gluten-free all-purpose flour blend (like Bob’s Red Mill or King Arthur) works best. Look for one that includes xanthan gum or add ½ teaspoon per cup.

Can I make this cake dairy-free or vegan?
Yes. Use vegan butter and plant milk like almond or oat. To make it vegan, you’ll also need an egg replacer—flax eggs or applesauce can work, though texture may vary slightly.

Is rhubarb poisonous? Which part is safe to eat?
Only the stalks are edible. The leaves are toxic and should always be discarded.

How do I make sure my cake stays moist without gluten?
Use room temperature eggs and milk, avoid overmixing, and don’t overbake. You can also add a spoonful of yogurt or sour cream for extra moisture.

Tried It Already? Let’s Hear Your Twist!

We’d love to hear from you!
Did you bake this Gluten Free Rhubarb Crumb Cake with a twist? Maybe you added strawberries, swapped the sugar, or made it vegan? Tell us how it went in the comments below!

If you’re craving more cozy, feel-good bakes, check out our Apple Cinnamon Oatmeal Cake for chilly mornings or try a slice of our Strawberry Almond Coffee Cake—perfect with your next cup of tea.

Sharing your version helps others bake better too—so let’s hear what you loved most!