As I write this post, there is a Blueberry Rhubarb Streusel Cake in the oven. I should have eaten dinner before I started baking, because the aroma is driving me mad.
It will be part of our Father’s Day lunch with friends, after vichyssoise, chicken salad, vegetables, and good bread. If I get the chance, I might come up with an appetizer or two as well. But the star of the show will be this cake.
The idea for this cake started with rhubarb. This rather bizarre-looking fruit (at least to me) is only in season for a few months around the mid-Atlantic US, where I live. The Kitchn (one of my favorite food information sites) says rhubarb is in season from mid-spring throughout the summer, with a prime season of three months from April through June. Maybe that’s true in theory. However, in my neighborhood, rhubarb only seems to be in stores in May and June. So when I saw it last week, I pounced.
Originally I planned a rhubarb crisp or crumble. But I thought those desserts weren’t quite festive enough for Father’s Day. Then I got fixated on streusel. Soon, I was checking out coffee cake recipes, pondering how to include rhubarb in the cake, and researching streusel.
In the end, this cake is not from any one recipe. But I would be remiss if I didn’t credit the inspiration that I got from this plum streusel coffeecake with a little help from these rhubarb strawberry streusel bars.
It may seem as though the cake has quite a few ingredients. Still, with the exception of rhubarb and maybe the blueberries, they are all pantry staples if you like to bake. The streusel is really only five ingredients. I put the confectioner’s sugar here because it goes on top of the streusel, but listed it after the cake because you don’t need it until the cake has cooled and you’re ready to serve it.
The cake itself is a simple coffee cake.
If you’re into streusel and want to know what differentiates it from crumb topping, you should read this post. Although I did find the streusel vs. crumb topping discussion helpful, I have to note that this streusel uses melted, rather than cold, butter. The post is just wrong when it says that melted butter causes streusel to flatten out. My secret is letting the streusel sit for a few minutes, then crumbling it with your fingers. It works. Don’t trust me – try it.
My blueberry rhubarb streusel recipe is a three-layer affair, almost equally divided between coffee cake, fruit and streusel.
As you can see, there is just enough cake in this Blueberry Rhubarb Streusel Cake to give the fruit and streusel a base to sit on. I consider streusel to be one of the great joys of eating coffee cake, so adding as much of it as I could reasonably put on top of this cake made me incredibly happy.
And speaking of happy, my beloved looked pretty happy when he wandered into the kitchen and discovered this cake baking for our Father’s Day lunch. Which made me even happier.
Blueberry Rhubarb Streusel Cake
A moist cake layered with fruit and streusel. It's perfect for celebrations or weekend munching.
Ingredients
Streusel
- 1 & 3/4 cups flour
- 3/4 cup light brown sugar, firmly packed
- 1 teaspoon cinnamon
- 1/4 teaspoon ground nutmeg
- 12 tablespoons unsalted butter, melted (1 1/2 sticks or 3/4 cup)
Cake (Batter and Fruit)
- 8 ounces rhubarb, cut into pieces about 1/3-inch thick About 2 cups. Be careful to only use the red stalk of the rhubarb - the leaves are poisonous!!
- 8 ounces blueberries About 2 cups
- 1 tablespoon fresh lemon juice
- 3/4 cup granulated (white) sugar, divided
- 1 1/4 cups flour
- 1 teaspoon baking powder
- 1/2 teaspoon fine sea salt
- 1/3 cup canola (or similar) oil
- 4 tablespoons unsalted butter, at room temperature
- 2 large eggs
- 1 teaspoon vanilla
- 1/3 cup sour cream
- 2-3 tablespoons confectioners sugar For sifting over cake just before serving.)
Instructions
- Preheat oven to 350°F. and butter and flour a 9-inch round or square baking pan at least 2 inches deep.
Streusel
- Mix the flour, sugar, cinnamon and nutmeg. Pour the melted butter over the mixture and toss with a rubber spatula just until it forms large crumbs. Set aside.
Cake
- Mix the rhubarb pieces, blueberries, lemon juice and ¼ cup sugar in a bowl and set aside.
- Whisk together the flour, baking powder, and salt and set aside.
Put the butter, canola oil, and sugar in a medium bowl. Beat them with an electric mixer or whisk until the mixture becomes light and fluffy (about 2 minutes with an electric mixer.) Add the sour cream and mix until combined. Then add the eggs, one at a time, beating well after each addition, and then vanilla. Sift in the dry ingredients and mix them in until just combined.
- Spread the cake batter in the pan, smoothing the top so that it is even and pushing the batter out to the edges of the pan. (The batter is spoonable, not runny.) Using a slotted spoon to drain any juices, spread the fruit over the batter.
- Spread the streusel over the fruit, using your hands to sprinkle it and break up the pieces into irregularly shaped pieces of varying sizes.
- Bake the cake in middle of oven for 1 hour 10 minutes, or until a tester comes out clean. Cool the cake completely in the pan on a wire rack. Once cooled, run a knife around the edges, put a cutting board or large flat plate on the top and flip the cake out of the pan. Then turn it right side up with another plate or a platter.
- Just before serving (at room temperature), sift confectioners sugar on top.
Sandra says
Hello Laura, I am in New Zealand where rhubarb grows all year around. I like it cut into 2 inch lengths, put in single row in shallow baking dish, sprinkle with brown sugar then pour some orange juice over it (just enough to half cover the rhubarb). Cover with foil and bake for approx 20 mins – needs to be just soft but not mushy.
Laura says
Sandra, Oooh, I envy you. I was just talking to a friend about how we can’t even find rhubarb into late June around us (Mid-Atlantic U.S.) Love your method for quickly cooking rhubarb. It sounds simple and wonderful. Of course, once the rhubarb is soft and cooked, you can always use it as a topping for a coffee or pound cake (says the cake lover:) Thanks for stopping by.
Nancy says
This recipe is AMAZING!!! I’m in rhubarb-laden New England & had frozen blueberries to use up. I’m newly gluten-free due to Celiac Disease and as a someone who loves to bake, am experimenting with gluten-free baking. Lots of trial & LOTS of error 😲 Everything I’ve read says you can’t just substitute gf flour in normal recipes. Well I did. And it worked. SOOO good. I doubled the recipe cuz I’m brave like that. I used 1/2 almond flour blend (added 1/4 tsp xanthan gum per cup) and 1/2 Better Batter (which includes xanthan gum), and because I can’t leave well enough alone, I used Trivia Baking Blend. Used a 9×13 pan, baked as directed, was done at 70 minutes. Thank you so very much for this recipe. It’s a keeper!
Laura says
Nancy, I love your spirit of adventure when it comes to gluten-free baking and I’m so happy that this recipe worked well for you. I’m a rhubarb fan too, but not in a place where I get a lot of it. When I do, it’s going straight into this cake, or crisp, or pie, or ….
Sarah says
First time making this recipe… it was a fantastic success! My grand-daughter and I are anxious to give the gluten-free substitutions given by Nancy a try. This recipe is a real KEEPER!
I discovered a wonderful drink made from residual by-products of this baking project. I cut up the half lemon left after juicing and used it to infuse some water. I cut up the rhubarb and combined the blueberries, sugar and lemon juice the night before I made the cake. After putting the cake in the oven this morning, I poured the juice leftover from the rhubarb/blueberry mixture into the lemon infused water. It’s delicious (and a great reward for the baker)!
Laura says
Sarah, First of all, many thanks for your comments about the recipe. It really makes my day when a reader enjoys a recipe. And the idea that you and your granddaughter bake together puts a smile on my face for sure!
As to your drink with the lemon, rhubarb and blueberry juice – sounds fantastic. I’ll have to try it next time I make the cake.
Laura M says
I agree with Sarah – this recipe is a keeper! I’ve made it several times with other fruit combinations (peach&raspberry, peach&blueberry) and adjusted lemon juice/zest to maintain some tartness.
Laura says
Laura M – Wow, I’m delighted that you’ve made this several times. Carry on 🙂
Amy says
can i freeze this cake? it sounds AMAZING.
Laura says
I haven’t frozen it, but it should freeze just fine. When freezing baked goods, it’s best to use a layer of paper (waxed, parchment of similar) between the cake and a plastic freezer bag. Otherwise, the cake takes on a peculiar smell after a while.
Deborah B says
Fabulous recipe, Made it yesterday with our second batch of early rhubarb and bb’s from the freezer. I’m in Vancouver British Columbia and spring comes early.
Only alteration was to cut the strudel topping in half for our waistlines sake, and I did add a 1/4 tsp of nutmeg to the batter, ‘cause I love it. I find blueberries can be pretty bland on their own, but this was so tasty, and will take Laura’s suggestion and try it with other fruits like peaches and apricots.
Laura says
Deborah – Glad you enjoyed it.