Rhubarb coffee cake is one of those simple bakes I keep coming back to when I want something cozy but not fussy. It’s a tender sour cream cake with a tangy rhubarb layer and a thick cinnamon streusel that gives you that classic crumb cake top.
The flavor is sweet and buttery with little pops of tart rhubarb, and the texture stays soft and moist for days thanks to the sour cream. I like this version because the rhubarb doesn’t disappear into the batter, and the streusel is generous enough to feel like it matters.
I usually serve this as a weekend breakfast cake or an easy afternoon snack with coffee or tea. It’s also great to bring to a spring get-together when rhubarb is around and you want something familiar but a little different.
Why You’ll Love This Recipe
Real crumb-topping situation: The streusel bakes up thick and buttery, with those little crunchy bits that make coffee cake worth making.
Tangy-sweet rhubarb layer: Rhubarb gives the cake a bright, tart edge that keeps the whole pan from tasting one-note.
Moist cake texture: Sour cream keeps the crumb soft and tender, even after it’s fully cooled.
Easy 9×13 format: This is the kind of cake I make when I want clean slices for sharing, no layering cakes or decorating.
Glaze is optional: You can leave it plain for a more classic coffee-cake feel, or add a quick drizzle if you want it a little sweeter.
Ingredients You’ll Need
Streusel Topping
- All-purpose flour: I use regular flour here. It’s what helps the streusel clump up instead of melting into the cake.
- Brown sugar: Light or dark brown sugar both work. Dark brown gives a slightly deeper molasses taste.
- Ground cinnamon: This is the main flavor in the topping, so use cinnamon you actually like.
- Salt: Don’t skip it. It keeps the streusel from tasting flat and overly sweet.
- Unsalted butter: Melted butter makes this topping quick and no-mess. If you only have salted butter, just go a little lighter on added salt.
Rhubarb Layer
- Rhubarb: Fresh is great, but frozen works too—just thaw and drain it well so the cake doesn’t get soggy.
- Granulated sugar: Rhubarb needs a bit of sugar to take the sharp edge off. This amount keeps it tart but not harsh.
- All-purpose flour: A little flour helps soak up juices as it bakes so the layer stays more jammy than watery.
Cake Batter
- All-purpose flour: I stick with regular flour for this cake. It gives you a sturdy crumb that can hold up to the fruit layer.
- Baking powder: Helps the cake lift and stay light.
- Baking soda: Works with the sour cream for a nice rise and tender texture.
- Salt: Brings the buttery flavor forward and keeps the sweetness in check.
- Unsalted butter: Softened butter creams best with the sugar. If it’s too warm and greasy, the texture won’t be as nice.
- Granulated sugar: Classic choice here. It sweetens the cake without getting in the way of the rhubarb.
- Eggs: Use large eggs if you can. They help the batter hold together and bake up evenly.
- Vanilla extract: Simple but important. It rounds out the tang from the sour cream and rhubarb.
- Sour cream: This is what makes the cake moist and tender. Plain Greek yogurt works too if that’s what you have.
Optional Glaze
- Powdered sugar: Makes a smooth, quick glaze that sets up nicely on top.
- Milk: Start with less and add more as needed. A tiny change makes it go from drizzle to icing fast.
- Vanilla extract: Just a little keeps the glaze from tasting like plain sugar.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F and grease a 9×13-inch baking pan.
- Mix the streusel: Stir the flour, brown sugar, cinnamon, and salt together, then add the melted butter and mix until clumpy. Set aside.
- Mix the rhubarb: Toss the diced rhubarb with the granulated sugar and flour until evenly coated. Set aside.
- Mix the dry ingredients: Whisk the flour, baking powder, baking soda, and salt together in a medium bowl.
- Cream the butter and sugar: Beat the softened butter and granulated sugar until light and fluffy.
- Add the eggs and vanilla: Beat in the eggs one at a time, then mix in the vanilla extract.
- Add the sour cream: Mix in the sour cream until the batter looks smooth.
- Add the dry ingredients: Stir in the dry ingredients just until combined. Stop as soon as you don’t see dry flour.
- Spread the batter: Spread half of the batter into the prepared pan.
- Add the rhubarb: Distribute the rhubarb evenly over the batter.
- Add the remaining batter: Drop the rest of the batter over the rhubarb in spoonfuls, then gently spread to cover.
- Add the streusel: Sprinkle the streusel evenly over the top.
- Bake: Bake for about 40 to 50 minutes, until a toothpick inserted in the center comes out clean and the top is golden. If it’s browning too fast, loosely cover with foil for the last 10 minutes.
- Cool: Cool for at least 20 minutes before slicing.
- Glaze: If using the glaze, whisk the powdered sugar, milk, and vanilla together, then drizzle over the warm or cooled cake.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Drain frozen rhubarb really well. Frozen rhubarb is convenient, but it can carry a lot of water. Thaw it, drain it, and pat it dry so the middle layer doesn’t get too wet.
Don’t overmix after adding the flour. Once the dry ingredients go in, stir just until you don’t see flour. Overmixing makes coffee cake bake up a little tougher than it needs to be.
Drop the top batter in spoonfuls. It’s easier to cover the rhubarb by dotting the batter around the pan first, then gently spreading it. If you try to spread it all at once, it can drag the fruit around.
Watch the streusel near the end. Brown sugar can darken quickly, especially if your pan runs hot. Foil over the top for the last few minutes is enough to keep it from getting too dark.
Add a little spice to the batter if you want. I like a teaspoon of cinnamon in the cake for a warmer flavor, and cardamom is nice too if you want something slightly different.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Coffee or tea: This is the obvious one, but it’s true. I like it with black coffee or an iced latte if it’s warm out.
- Whipped cream: A small spoonful on the side is really nice if you’re serving it as dessert. It softens the tart rhubarb bite.
- Fresh berries: Strawberries or raspberries are great next to this cake, especially if you want the plate to feel a little lighter.
- Vanilla ice cream: If you warm a slice slightly, vanilla ice cream on top is simple and very good.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store the cake covered at room temperature for up to 2 days. I usually keep it right in the pan with foil over the top. The streusel stays nicest the first day, but it’s still good the next day.
For longer storage, refrigerate for up to 5 days. The cake firms up a bit in the fridge, so I like to let slices sit out for a few minutes before eating.
Rewarm individual slices in the microwave for a few seconds if you like it warm. You can also warm larger portions in a low oven until heated through.
If you want to plan ahead, you can bake the cake a day early and glaze it right before serving. I prefer glazing closer to serving so the top doesn’t get too soft.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
Can I use frozen rhubarb?
Yes. Thaw it first and drain it really well, then pat it dry with paper towels. Frozen rhubarb can add a lot of extra moisture if you don’t get rid of the liquid.
Can I swap the sour cream for Greek yogurt?
You can use plain Greek yogurt in the same amount. I like full-fat if you have it, but low-fat works too.
How do I know when the coffee cake is done?
The top should be golden and a toothpick inserted near the center should come out clean. If you hit a soft rhubarb spot, test in a couple places so you’re not judging it off the fruit layer.
Do I have to add the glaze?
Nope. I like the cake plain for breakfast, and I add the glaze when I’m serving it more like dessert or bringing it to share.
Why did my middle turn out a little wet?
This usually happens when the rhubarb is extra juicy (or frozen and not drained well), or if the cake needed a few more minutes in the oven. Next time, drain the rhubarb better and bake until the center tests clean.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Rhubarb Coffee Cake Coffee Cake
INGREDIENTS
Streusel Topping
- 1 cup all purpose flour
- 3/4 cup brown sugar
- 1 tsp ground cinnamon
- 1/4 tsp salt
- 6 tbsp unsalted butter melted.
Rhubarb Layer
- 2 1/2 cups rhubarb diced
- 1/3 cup granulated sugar
- 1 tbsp all purpose flour.
Cake Batter
- 2 cups all purpose flour
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp salt
- 1/2 cup unsalted butter softened
- 1 cup granulated sugar
- 2 large eggs
- 1 tsp vanilla extract
- 1 cup sour cream.
Optional Glaze
- 3/4 cup powdered sugar
- 1 to 2 tbsp milk
- 1/2 tsp vanilla extract.
INSTRUCTIONS
Prepare Pan and Oven
- preheat oven to 350 F and grease a 9x13 inch baking pan
- mix streusel topping ingredients until clumpy and set aside
- toss rhubarb with sugar and flour until evenly coated and set aside.
Mix Batter and Assemble
- whisk flour baking powder baking soda and salt in a bowl
- cream butter and sugar until light then beat in eggs one at a time and mix in vanilla
- mix in sour cream then add dry ingredients and stir just until combined
- spread half of batter in pan then distribute rhubarb evenly over batter
- drop remaining batter over rhubarb in spoonfuls and gently spread to cover
- sprinkle streusel evenly over the top.
Bake and Finish
- bake until a toothpick inserted in the center comes out clean and top is golden about 40 to 50 minutes
- cool at least 20 minutes before slicing
- if using glaze whisk powdered sugar milk and vanilla and drizzle over warm or cooled cake.
