Rhubarb coffee cake is one of those cozy bakes that tastes like spring the second you take a bite. The cake is soft and buttery with that perfect sweet-tart rhubarb flavor running through every slice, and the cinnamon streusel on top adds a crumbly finish that makes it feel bakery-worthy. If you’ve been searching for a rhubarb coffee cake that is easy to make but still looks impressive, this is the one to keep on repeat.
Rhubarb can be tricky because it releases moisture as it bakes, so the goal is a cake that stays tender without turning wet in the center. I’ve tested fruit coffee cakes enough to know the small details matter, especially measuring the rhubarb properly, not overmixing the batter, and baking until the crumb is set. When you do it right, you get a cake that’s rich and fluffy with pops of tangy rhubarb in every bite.
This rhubarb crumb cake works beautifully for brunch, afternoon coffee, or an easy dessert after dinner. The streusel bakes into a golden topping that stays crisp on top while the cake stays soft underneath. Serve it slightly warm, or let it cool completely and slice it into neat squares for a make-ahead treat that feels homemade in the best way
Why You’ll Love This Rhubarb Coffee Cake
- Perfect balance of sweet and tart flavors.
- Soft, buttery crumb with juicy rhubarb throughout.
- Crunchy cinnamon streusel topping in every bite.
- Easy to make in one bowl (plus streusel bowl).
- Great for brunch, potlucks, or dessert.
- Tastes even better the next day.
Expert Tips for the Best Rhubarb Coffee Cake
- Use fresh or thawed rhubarb. If using frozen rhubarb, thaw and drain well so the cake doesn’t turn watery.
- Cut rhubarb evenly. Small, even pieces bake consistently and prevent soggy pockets.
- Do not overmix. Overmixing develops gluten and makes the cake dense instead of tender.
- Bake until fully set. Coffee cakes can look done on top but still be underbaked in the center.
- Let it cool before slicing. Cooling helps the crumb set and prevents it from falling apart.
Quick Troubleshooting
- Cake is gummy in the middle: Rhubarb released moisture and the cake didn’t bake long enough. Bake 5–10 minutes longer next time and check the center.
- Streusel melted into the cake: Butter was too warm or streusel crumbs were too fine. Use cold butter and keep chunks pea-sized.
- Rhubarb sank: Batter was overmixed or too thin. Fold rhubarb in gently and avoid adding extra liquid.
Ingredients for Rhubarb Coffee Cake
For the Streusel Topping
- 1/2 cup (100 g) brown sugar
- 1/3 cup (40 g) all-purpose flour
- 1 tsp ground cinnamon
- pinch of salt
- 1/4 cup (57 g) cold unsalted butter, cubed
For the Coffee Cake
- 1 1/2 cups (190 g) all-purpose flour
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1/4 tsp salt
- 1/2 cup (115 g) unsalted butter, softened
- 3/4 cup (150 g) granulated sugar
- 1 large egg
- 2 tsp vanilla extract
- 1/2 cup (120 g) sour cream (or plain Greek yogurt)
- 1/4 cup (60 ml) milk
- 1 1/2 cups chopped rhubarb
How to Make Rhubarb Coffee Cake
Step 1: Prep the pan and oven. Preheat your oven to 350°F (175°C). Grease an 8×8-inch baking dish and line with parchment if you want easy lifting. This cake bakes best in a square dish because it gives you a thick, soft crumb and clean slices.
Step 2: Make the cinnamon streusel. In a bowl, mix brown sugar, flour, cinnamon, and salt. Add the cold butter cubes and rub them into the dry ingredients using your fingertips until crumbly. You want a mix of fine crumbs and bigger buttery clumps, because the clumps bake into that crisp bakery-style topping.
Step 3: Mix the dry ingredients. In a medium bowl, whisk together flour, baking powder, baking soda, and salt. This keeps the cake evenly leavened and prevents dense patches in the final crumb.
Step 4: Cream the butter and sugar. In a large bowl, beat softened butter and sugar until light and fluffy, about 2 minutes. This step matters because it builds a tender texture before the flour goes in.
Step 5: Add egg and vanilla. Beat in the egg until smooth, then mix in vanilla. Scrape the bowl to make sure everything blends evenly so your batter stays consistent.
Step 6: Finish the batter. Add the dry ingredients in 2 additions, alternating with sour cream and milk, mixing just until combined. The batter should be thick and creamy. Stop mixing as soon as the flour disappears so the cake stays soft.
Step 7: Fold in the rhubarb. Add the chopped rhubarb and fold gently with a spatula. You want the rhubarb evenly distributed without breaking it down or thinning the batter.
Step 8: Assemble and bake. Spread batter evenly into the prepared pan. Sprinkle the streusel evenly on top, including the bigger clumps. Bake for 40 to 50 minutes, or until a toothpick comes out clean and the center feels set.
Step 9: Cool and slice. Cool the coffee cake in the pan for at least 30 minutes before slicing. This gives the rhubarb time to settle and helps the cake hold together in neat squares.
Storage and Make-Ahead Tips for Rhubarb Coffee Cake
- Store covered at room temperature for up to 2 days.
- Refrigerate for up to 5 days for best freshness.
- Reheat slices in the microwave for 10–15 seconds to soften the crumb.
- Freeze individual squares wrapped tightly for up to 2 months.
- Streusel stays best when stored loosely covered instead of airtight (prevents soggy topping).
FAQs About Rhubarb Coffee Cake
Frozen rhubarb works well, but it needs to be thawed and drained first to avoid excess moisture in the batter. After thawing, blot it lightly with paper towels so it doesn’t add extra liquid. Frozen rhubarb is often softer than fresh, so keep the pieces slightly larger so they don’t disappear into the cake. If the batter looks thin after adding it, bake a little longer and check the center carefully.
A soggy center usually happens when the rhubarb releases extra moisture and the cake doesn’t bake long enough to set. Coffee cakes can look done on top because of the streusel, but the center may still be underbaked. Check the cake with a toothpick in the middle and look for a clean result, not wet batter. If needed, cover loosely with foil and bake 5–10 minutes longer to finish cooking without burning the topping.
An 8×8-inch pan gives the thickest crumb and the cleanest squares, which makes this recipe feel more bakery-style. A 9×9-inch pan works too, but the cake will bake faster and be a little thinner. If using a 9×13-inch pan, you should double the recipe or the cake will be too flat and dry. Metal pans bake more evenly and create a slightly better edge texture than glass.
This cake is a great make-ahead recipe because the flavor improves after a few hours once the rhubarb settles. You can bake it the day before and store it covered at room temperature overnight. For longer storage, refrigerate it and reheat slices briefly so it tastes fresh again. If making ahead for brunch, bake the night before and cut in the morning for the cleanest slices.
Crunchy streusel starts with cold butter and a crumb mixture that includes some bigger clumps. If the butter is too soft, the streusel melts into the batter instead of staying crisp. Storing the cake loosely covered also helps keep the topping from steaming and turning soft. If it loses crunch, a quick reheat in the oven at 300°F for 5–7 minutes brings the topping back to life.
Adding strawberries is a great idea because strawberry and rhubarb are a classic combo, but it changes the moisture level. If using strawberries, reduce the amount of rhubarb slightly and use chopped berries, not sliced, so they don’t leak as much juice. Bake until the center is fully set since the extra fruit will extend bake time. For the cleanest texture, keep strawberries to about 1/2 cup and avoid very ripe berries.
More Dessert Recipes You’ll Love
- Strawberry Rhubarb Cobbler
- Traditional Bakewell Tart Recipe (Almond Frangipane Tart)
- Old Fashioned Strawberry Rhubarb Pie with Streusel
- Dutch Apple Crumble Pie With Oats
- Coconut Cream Pie With Coconut Milk Recipe
- Strawberry Pavlova Cake Recipe With Cream Of Tartar
- Apple Crisp Recipe With Oats
Rhubarb Coffee Cake
Equipment
- 8×8-inch baking dish
- Mixing bowls
- Whisk
- Electric mixer
- Rubber spatula
Ingredients
Streusel Topping
- 1/2 cup brown sugar
- 1/3 cup all-purpose flour
- 1 tsp cinnamon
- pinch of salt
- 1/4 cup cold unsalted butter cubed
Coffee Cake
- 1 1/2 cups all-purpose flour
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1/4 tsp salt
- 1/2 cup unsalted butter softened
- 3/4 cup granulated sugar
- 1 large egg
- 2 tsp vanilla extract
- 1/2 cup sour cream
- 1/4 cup milk
- 1 1/2 cups chopped rhubarb
Instructions
- Preheat your oven to 350°F (175°C). Grease an 8×8-inch baking dish and line with parchment if you want easy lifting. This cake bakes best in a square dish because it gives you a thick, soft crumb and clean slices.
- In a bowl, mix brown sugar, flour, cinnamon, and salt. Add the cold butter cubes and rub them into the dry ingredients using your fingertips until crumbly. You want a mix of fine crumbs and bigger buttery clumps, because the clumps bake into that crisp bakery-style topping.
- In a medium bowl, whisk together flour, baking powder, baking soda, and salt. This keeps the cake evenly leavened and prevents dense patches in the final crumb.
- In a large bowl, beat softened butter and sugar until light and fluffy, about 2 minutes. This step matters because it builds a tender texture before the flour goes in.
- Beat in the egg until smooth, then mix in vanilla. Scrape the bowl to make sure everything blends evenly so your batter stays consistent.
- Add the dry ingredients in 2 additions, alternating with sour cream and milk, mixing just until combined. The batter should be thick and creamy. Stop mixing as soon as the flour disappears so the cake stays soft.
- Add the chopped rhubarb and fold gently with a spatula. You want the rhubarb evenly distributed without breaking it down or thinning the batter.
- Spread batter evenly into the prepared pan. Sprinkle the streusel evenly on top, including the bigger clumps. Bake for 40 to 50 minutes, or until a toothpick comes out clean and the center feels set.
- Cool the coffee cake in the pan for at least 30 minutes before slicing. This gives the rhubarb time to settle and helps the cake hold together in neat squares.
Notes
- Frozen rhubarb works well if thawed and drained first.
- For best texture, avoid overmixing the batter after adding flour.
- Let the cake cool before slicing so the crumb sets properly.
- Store loosely covered to keep streusel crunchy longer.
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