Rhubarb Spoon Cake – A Step By Step Guide To Rhubarb Cake with Cake Mix

Rhubarb Spoon Cake has the texture of a rhubarb sponge cake and is served like a rhubarb upside cake. The best part is that it’s a rhubarb cake using a cake mix and can be made with frozen or fresh rhubarb.

Rhubarb season is right around the corner here in Indiana. That means I’m using up all the frozen rhubarb in the freezer from last rhubarb season.  Not all rhubarb recipes work for frozen rhubarb which means I’m always on the lookout for recipes that use frozen rhubarb.

Rhubarb Spoon Cake Recipe

This easy rhubarb cake recipe from a church cookbook (Waynesburg Christian Church to be exact) caught my eye. I had ever seen a recipe for a rhubarb spoon cake. After conquering this recipe, let me explain more about it.

It uses a cake mix but the texture is more of sponge cake.  In addition, the topping is on the bottom, and it’s served upside down like a traditional upside down cake.

So the question is…is it a rhubarb sponge cake, a rhubarb spoon cake or a rhubarb upside down cake.  It’s actually all three!

How to serve Rhubarb Upside Down Cake?

Cut the cake, and flip the slice on the plate so the top becomes the bottom.  Scoop any excess rhubarb sauce from the pan, and dollop over the top. If desired, add whipped topping or whipped cream. Since this rhubarb cake is served upside down, the top isn’t all that pretty right out of the oven. I prefer to add an easy powdered sugar glaze to make it more aesthetically pleasing.  However, that is completely optional.  The flavor is perfect just as is too.

Ingredients Needed For Rhubarb Upside Down Cake with Cake Mix

• Cake Mix, yellow (or white cake mix)
• Large Eggs
• Oil
• Water
• Diced Rhubarb Stalk, either fresh or frozen (do not use leaves of rhubarb)
• Orange Juice
• Sugar
• Orange Zest
• Butter

For optional glaze:

• Powdered Sugar (confectioner’s sugar)
• Milk (or cream or half and half)
• Vanilla Extract

How to make rhubarb cake with cake mix

Step By Step Instructions

1. In a large bowl, prepare cake mix according to the instructions on the box.
2. Pour mixture into a greased 13 x 9 inch baking dish.
3. In a small saucepan, heat diced rhubarb, orange juice and sugar until it begins to simmer. Let simmer for 10 minutes or until the sauce thickens.
4. Pour the rhubarb sauce over top the prepared cake mix.
5. Bake in preheated oven for 30 to 35 minutes.
6. Let cool and eat as is or add optional glaze.
7. For glaze, whisk powdered sugar, milk and vanilla until smooth. Pour over warm cake and let harden. Try serving along side vanilla ice cream.

Storage Instructions

Let leftover cake cool completely. Cover tightly with a lid, and store at room temperature for up to 48 hours. Store in fridge to store for a longer period of time.

For the full ingredient list, amounts and instructions, scroll down to the recipe card at the bottom of this post. 

Recipe FAQs

• This rhubarb cake uses boxed cake mix. I recommend a white or yellow cake mix. Follow the instructions on the box to prepare the batter.
• Substitute pineapple juice for orange juice, if desired.
• Use fresh or frozen rhubarb for this rhubarb spoon cake.  If frozen is used, you may need to simmer the rhubarb sauce a bit longer to thicken it up.
• The powdered sugar glaze is completely optional.  I like to make it because it makes the top of the cake prettier; however, it is a rhubarb upside down cake so it’s served with the pretty rhubarb side up.  Either way is great!
• To serve, cut the cake and flip slice onto the plate so the top becomes the bottom. If any additional rhubarb sauce remains in the dish, spoon over top.
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Unique Rhubarb Recipes

Grandma’s Rhubarb Struesel

Rhubarb Coffee Cake

Strawberry Rhubarb Jam with Jello

Rhubarb Sour Cream Cake

Rhubarb Strawberry Fool

Check out even more rhubarb recipes in this post.