Rhubarb “Big Crumb” Coffeecake
Updated April 2, 2026
- Total Time
- 1 hour 30 minutes, plus cooling
- Rating
- Comments
- Read comments
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Ingredients
- Butter, for greasing pan
- ½pound rhubarb, trimmed
- ¼cup sugar
- 2teaspoons cornstarch
- ½teaspoon ground ginger
- ⅓cup dark brown sugar
- ⅓cup granulated sugar
- 1teaspoon ground cinnamon
- ½teaspoon ground ginger
- ⅛teaspoon salt
- ½cup melted butter
- 1¾cups cake flour
- ⅓cup sour cream
- 1large egg
- 1large egg yolk
- 2teaspoons vanilla extract
- 1cup cake flour
- ½cup sugar
- ½teaspoon baking soda
- ½teaspoon baking powder
- ¼teaspoon salt
- 6tablespoons softened butter, cut into 8 pieces
For the Rhubarb Filling
For the Crumbs
For the Cake
Nutritional analysis per serving (8 servings)
539 calories; 25 grams fat; 15 grams saturated fat; 0 grams trans fat; 7 grams monounsaturated fat; 1 gram polyunsaturated fat; 73 grams carbohydrates; 2 grams dietary fiber; 34 grams sugars; 6 grams protein; 231 milligrams sodium
Note: The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
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Preparation
- Step 1
Preheat oven to 325 degrees. Grease an 8-inch-square baking pan. For filling, slice rhubarb ½ inch thick and toss with sugar, cornstarch and ginger. Set aside.
- Step 2
To make crumbs, in a large bowl, whisk together sugars, spices, salt and butter until smooth. Stir in flour with a spatula. It will look like a solid dough.
- Step 3
To prepare cake, in a small bowl, stir together the sour cream, egg, egg yolk and vanilla. Using a mixer fitted with paddle attachment, mix together flour, sugar, baking soda, baking powder and salt. Add butter and a spoonful of sour cream mixture and mix on medium speed until flour is moistened. Increase speed and beat for 30 seconds. Add remaining sour cream mixture in two batches, beating for 20 seconds after each addition, and scraping down the sides of bowl with a spatula. Scoop out about ½ cup batter and set aside.
- Step 4
Scrape remaining batter into prepared pan. Spoon rhubarb over batter. Dollop set-aside batter over rhubarb; it does not have to be even.
- Step 5
Using your fingers, break topping mixture into big crumbs, about ½ inch to ¾ inch in size. They do not have to be uniform, but make sure most are around that size. Sprinkle over cake. Bake cake until a toothpick inserted into center comes out clean of batter (it might be moist from rhubarb), 45 to 55 minutes. Cool completely before serving.
Private Notes
Comments
Rhubarb, crumb and cake: The cake is excellent. I substituted plain, nonfat Greek yogurt for the sour cream and used Irish butter. The crumb topping was just okay; but it is not what I prefer in a coffee cake. Instead of being a sparkling, crunchy-sugary topping, the crumb tasted dense and drab from flour. With respect to rhubarb, a little more would be nice. So I'll definitely make the cake again, but with a different crumb topping and perhaps 3/4 lb rhubarb.
I’ve made this five times and when I use Swans Cake Flour the crumb is perfection. Twice I only had King Arthur Cake Flour and the crumb was hard and floury. Use Swans- it’s incredible.
Wow I found this recipe a bit overly complicated. So many bowls! And proportions seem off. Very little cake batter and mounds of crumb. I literally couldn't fit it all on top of the cake. My crumb also turned out sandy and did not form into a dough. Will halve the flour and add oats next time. Will also double the batter because I like more cake and less sugar topping.
FAN-TASTIC! 10/5. You like rhubarb, butter and a great crumb topping? Make this cake! That said, I did make a couple of adjustments - I will preempt the posters who often chime in with, “you didn’t make the recipe as it was written.” No in fact I didn’t. For those still reading, I bake every week and have become comfortable “personalizing” recipes based on our Sunday family dinner crew’s taste buds. Here’s where that popped up for this delicious cake. Used cake flour (Swan’s) in all parts of this recipe. Highly recommended! Used 5 heaping T’s of fresh, finely grated ginger (a grater box with small plate) mixed in with the rhubarb and sugar prep bowl. Used the same amount of ginger, 5T, in the crumb topping and omitted the cinnamon. Used 2/3 C of sugar in the cake. Used the called for amount of brown sugar and halved the white sugar in the crumb topping. I used WAY more rhubarb than recipe called for. 2 C of it Then, for the WIN, I made the rhubarb compote (NYT) and served that to our over the cake with homemade whipping cream. Let’s just say that the not quite 2 year old who was present, popped out a giddy, loud, unprompted, “TANK YOU” raising both arms, clenching his spoon above his head after the first bite. The 9 adults all responded in kind and we taught him the word “WOW!” This cake was a quasi religious, all age, positive group experience. If you, like me, wait all year for rhubarb to come into season, do yourself a favor with this one!
@SH check that. I used 1/3 C of sugar in the cake AND, use Mexican table cream instead of sour cream. Will do this again too.
Really super good. I made exactly as is EXCEPT followed the many comments advising less flower in the crumb. - I used a little bit less than a cup of cake flour (did not measure it exactly), added about 1/3 cup of oats and even less than that of finey chopped pecans. Top was perfect, crunchy and brown sugary. Not sandy, soft or mushy. It’s not too sweet, I often cut down on sugar and don’t feel like I had to on this.
It seems like 1 3/4 c flour in the crumb topping is too much. It had a floury taste. (Yes, I used cake flour). Especially since there is only 1 cup in the batter. I thought maybe they were mixed up, but the batter does not need more flour. I love the ginger and rhubarb together and I do not find it too sweet at all. Next time I would decrease the flour in the crumble. Maybe by 3/4 c. Need to check on the texture as I go.