I love how effortless this cake is to make—everything comes together in one bowl with no complicated steps. The sour cream keeps the cake incredibly soft, and the rhubarb adds a refreshing tartness that balances the sweetness. The nutmeg-sugar topping creates a subtle spiced crust that makes each slice even better.
Ingredients
(Note: All ingredient amounts are listed in the recipe card below.)
1 ½ cups packed brown sugar ¼ cup butter, softened 1 large egg 1 tablespoon vanilla extract 2 ⅓ cups all-purpose flour 1 teaspoon baking soda ½ teaspoon salt 4 cups chopped rhubarb 1 cup sour cream ⅓ cup white sugar ½ teaspoon ground nutmeg
Directions
I start by preheating the oven to 350 degrees F and greasing a 9×13-inch glass baking dish.
In a large bowl, I beat together the brown sugar and softened butter until well blended. I add the egg and vanilla and mix until smooth.
In a separate bowl, I sift the flour, baking soda, and salt together. I gradually stir this dry mixture into the butter mixture. I fold in the chopped rhubarb and the sour cream until everything is just combined.
I spread the batter evenly into the prepared baking dish.
In a small bowl, I mix the white sugar and nutmeg, then sprinkle this mixture evenly over the batter.
I bake the cake for about 40 minutes, or until a toothpick inserted into the center comes out clean.
Sometimes I add a pinch of cinnamon to the topping for extra warmth. I also like folding in a handful of chopped nuts for texture. If I want a lighter cake, I replace part of the sour cream with yogurt. A simple vanilla glaze drizzled over the cooled cake adds sweetness if I’m serving it as a dessert.
Storage/Reheating
I store the cake covered at room temperature for up to 2 days, or refrigerate it for up to 5 days. It reheats beautifully—just a few seconds in the microwave warms it without drying it out. The cake also freezes well; I wrap slices individually and thaw them whenever I want a quick treat.
FAQs
Can I use frozen rhubarb?
Yes, I use it straight from the freezer but blot excess moisture with a paper towel.
Can I add strawberries?
Absolutely—strawberries pair wonderfully with rhubarb.
Why is the cake so moist?
The sour cream and rhubarb keep the crumb tender and soft.
Can I reduce the sugar?
I can lower the brown sugar slightly, though the texture may change.
Should I peel the rhubarb?
I don’t peel it unless the stalks are very thick or fibrous.
Can I bake this in a metal pan?
Yes, I use a metal 9×13 pan; the cake may bake a few minutes faster.
Can I make cupcakes instead?
Yes, I adjust the bake time to about 18–22 minutes.
Can I use Greek yogurt instead of sour cream?
Yes, it works well and keeps the cake moist.
How do I prevent the rhubarb from sinking?
Coating the rhubarb lightly in a tablespoon of flour helps distribute it.
Can I double the recipe?
Yes, I bake it in two pans or a large sheet pan, adjusting the time as needed.
Conclusion
I love how this rhubarb stir cake transforms simple ingredients into a tender, flavorful dessert that highlights the bright, tart taste of rhubarb. It’s easy to make, delicious warm or chilled, and always a hit at brunch or family gatherings.
