Upside Down Rhubarb Cake

Name: Upside Down Rhubarb Cake
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American
Ingredients: 4oz (1/2 Cup) Butter, softened to room temperature; 200 Grams (1 Cup) Granulated Sugar; 2 Large Eggs, at room temperature; 180 Grams (1 1/2 Cups) Cake Flour; 1/2 Teaspoon Baking Soda; 1/2 Teaspoon Baking Powder; 1/4 Teaspoon Salt; 4oz (1/2 Cup) Sour Cream, at room temperature; 2oz (1/4 Cup) Whole Milk, at room temperature; 2 Teaspoons Pure Vanilla Extract; 2oz (4 Tablespoons) Butter, melted; 100 Grams (1/2 Cup) Granulated Sugar; 2 Cups Thinly Sliced Rhubarb; Serve with lightly whipped cream or ice cream

By Elizabeth Waterson // Apr 25, 2023 (Updated Sep 9, 2024) // 4 Comments

Jump to Recipe·5 from 2 reviews

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If you love rhubarb, look no further. This is the best rhubarb cake recipe out there! Learn how to make this upside-down rhubarb cake with step-by-step photos!

slice of rhubarb cake on a white plate with a fork on an light cream surface

When I made my upside-down granola cake recipe a few months ago I knew it was good but I didn't think my harsh critics (Lydia I am looking at you) would fall so hard for it. So when I was developing this rhubarb recipe I worked on a couple of different versions, folding rhubarb into the cake batter, and sprinkling rhubarb on top but I wasn't in love with and then it dawned on me why not take my delicious cake base for that granola cake? Success! This cake is so good.

The rhubarb gets sweetened and caramelized as it cooks in the oven and then the cake is super soft and moist!

close up of upside down rhubarb cake cut open on a white plate on an light cream surface

Let's get to the recipe

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Ingredients
Instructions
How to freeze
More rhubarb recipes
Recipe Card
Recipe Ratings & Comments

Ingredients

Butter. Your butter needs to be softened to room temperature for the cake batter but melted for the cake topping. Since this is a delicately flavored cake I find butter gives great flavor as opposed to using vegetable oil.
Granulated Sugar. The sugar is creamed with the butter for the cake batter and then also used to sweeten the rhubarb for the topping. I chose to use white sugar instead of brown sugar in this recipe to not have any caramel undertones distract you from the rhubarb flavor.
Large Eggs. For the eggs to be evenly incorporated into the creamed butter and sugar the eggs should be at room temperature. You can easily get your eggs at room temperature by placing them in a bowl of warm water for 5 minutes before you crack them.
Cake Flour. Cake flour has a lower protein content compared to all-purpose flour to create a delicious light cake.
Chemical Leavening Agents. You'll need both baking soda and baking powder to create the best lift without tasting metallicy. The baking soda is activated by the sour cream. But the baking powder is already activated.
Salt. Salt enhances all the flavor profiles of the other ingredients. Don't skip it!
Sour Cream. The sour cream needs to be at room temperature.
Whole Milk. The whole milk also needs to be at room temperature
Pure Vanilla Extract. Don't use imitation vanilla, pure vanilla extract is best.
Fresh Rhubarb. You'll need to make sure you have thinly sliced rhubarb so it breaks down as it bakes. I have never tested this recipe with frozen rhubarb.

We love the cake as is but serve it with a little bit of whipped cream or ice cream to add a little extraness.

You could add a ½ teaspoon of ground cinnamon if you love the cinnamon flavor.

For ingredient quantities please reference the recipe card below. On the recipe card there is a button for US or M (Metric) measurements.

Instructions

Preheat the oven to 350F/180C.

In the bowl of an electric stand mixer fitted with a paddle attachment or a large bowl with a handheld electric mixer combine the butter and sugar for a couple of minutes until they are completely creamed together and lightened in texture.

mixer creaming butter and sugar together on an light cream surface with a blue linen

Scrape the sides of the bowl and add one egg and mix on medium speed until no trace of egg yolk remains. Add the second egg and mix again until no trace of egg yolk remains.

eggs added one at a time to creamed butter and sugar on an light cream surface with a blue linen

wet ingredients mixed together in a glass bowl on an light cream surface with a blue linen

In a separate large bowl combine the cake flour, baking soda, baking powder, and salt. In another bowl or a liquid measuring cup with a pour spout combine the sour cream, whole milk, and vanilla extract.

dry ingredients and liquid ingredients measured out on a light cream surface

Stir in ⅓ of the dry cake flour mixture to the butter mixture and mix until just combined then, add half of the sour cream mixture and mix until just combined. Add another third of the dry ingredients followed by the wet and lastly the remaining dry, do not overmix the cake batter.

dry ingredients added then liquid ingredients added to cake batter on an light cream surface

cake batter in a glass bowl on an light cream surface

Heavily grease a 9-inch cake pan with nonstick baking spray, make sure it is a thick layer. Add the melted butter and swirl to coat the bottom of the pan and then sprinkle the granulated sugar on top. Your rhubarb stalks should be cut into small pieces, if your stalk is especially thick then I cut it in half then dice it into smaller pieces. Add the rhubarb in an even layer then add the cake batter to the prepared pan. I use an offset spatula to spread the cake batter into an even layer.

butter, sugar and rhubarb added to the bottom of a cake pan on an light cream surface

rhubarb cake before baking on an light cream surface with a blue linen

Bake the cake for 35 to 40 minutes, if you gently press the top it should spring back right away or if you insert a toothpick there should be no wet batter.

rhubarb cake served on a white plate on an light cream surface with a blue linen

Let the baking dish cool on a wire rack for five minutes then take an offset spatula and gently run it around the sides of the cake to loosen it from the pan. Now place a serving plate upside down on top of the cake and then invert the cake onto the plate to cool completely. The cake is best eaten the day it is made but leftovers will keep in an air-tight container for up to 3 days.

How to freeze

You can freeze this rhubarb cake by letting it cool completely then, wrapping it in plastic wrap tightly, twice, then once in aluminum foil to help prevent freezer burn. Due to the fruit, I prefer not to freeze this cake but you can do it and sacrifice a little on the beauty and taste of this cake.

More rhubarb recipes

My rhubarb crumble is a classic British treat we grew up with.

My sisters fell in love with this rhubarb custard pie.

For breakfast check out my rhubarb muffins recipe!

ice cream scoop on top of a slice of rhubarb cake on a white plate with a fork on an light cream surface with a blue linen

★★★★★ Please let me know if you make this recipe by leaving a star rating and comment below!

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Recipe Card