These rhubarb cupcakes are a bright springtime treat—soft vanilla cupcakes filled with an easy homemade rhubarb jam and finished with a subtly pink rhubarb buttercream.
There are three parts to these cupcakes: a simple vanilla cupcake, a small-batch rhubarb jam used as the filling, and a rhubarb-flavored buttercream that incorporates some of the jam. While a bit more involved than a plain cupcake, the steps are straightforward and the result is worth the effort.
The cupcakes
These vanilla cupcakes are quick and forgiving—no creaming, no melted butter, no separating eggs. Mix the dry ingredients in one bowl, whisk the wet ingredients in another, then combine until just mixed. The batter will be thin, and that’s normal.
After baking and cooling, use a teaspoon to remove a small plug of cake from the center of each cupcake. Reserve those little pieces to cover the jam filling.
The filling
The rhubarb jam is made on the stovetop with rhubarb, sugar, lemon and a pinch of salt. Simmer until the fruit breaks down and the mixture thickens, then finish with lemon juice. If you can’t source fresh rhubarb or prefer to skip making jam, 3/4 cup store-bought rhubarb jam can be used instead.
The frosting
The frosting is a classic buttercream boosted with 1/2 cup of the rhubarb jam, which lightens the sweetness and gives a delicate pink hue. Beat the room-temperature butter with jam and vanilla, then slowly add powdered sugar until the frosting is light and fluffy. It pipes nicely and looks very pretty on these dainty cupcakes—ideal for Mother’s Day, showers, or spring gatherings.
About rhubarb
Rhubarb is tart and usually cooked with sugar or paired with sweet fruit to balance its sourness. The edible part is the stalks—long, often red or green—and they contain most of the antioxidants. The large green leaves are toxic due to oxalic acid, so always discard them and use only the stalks.
Store rhubarb wrapped in plastic in the refrigerator for up to two weeks. It’s a seasonal spring and early summer ingredient that complements berries, citrus and ginger, and it works beautifully in jams, compotes, desserts and drinks.
How to prepare rhubarb
Rinse the stalks, trim the ends, and chop them into roughly 1/2-inch pieces—similar to chopping celery. Peeling is optional and usually unnecessary; the red skin holds color and nutrients. Once prepped, cook the rhubarb into the jam or compote called for in the recipe.
Other rhubarb ideas
- Use rhubarb in compotes, fruit leathers, crisps and crisps paired with berries.
- Swap honey or maple syrup in simple rhubarb compotes for a different flavor profile.
- Try rhubarb-based drinks and cocktails for a tart-sweet twist.
These rhubarb cupcakes celebrate seasonal stalks and make a lovely, slightly tangy dessert when rhubarb is at its best.
If you make these cupcakes, I’d love to see a photo—share your creations on social media and tag your posts so they’re easy to find!
Rhubarb Cupcakes
Ingredients
For the jam filling:
- 4 cups (500 grams) rhubarb, cut into ½” pieces
- 1 cup (200 grams) granulated sugar
- 1 1/2 tablespoons lemon juice (about 1/2 medium lemon)
- 1/2 tablespoon lemon zest (about 1/2 medium lemon)
- pinch salt
For the cupcakes:
- 1 cup (125 grams) all-purpose flour
- ⅔ cup (166 grams) granulated sugar
- 1 teaspoon baking powder
- 1/8 teaspoon salt
- ½ cup (120 ml) milk
- ¼ cup (60 ml) vegetable oil
- 2 teaspoons vanilla extract
- 1 large egg (50 grams)
- ⅓ cup (80 ml) hot water
For the frosting:
- 1/4 cup (56 grams) unsalted butter, softened
- 1 teaspoon vanilla extract
- 1/2 cup rhubarb jam (from above)
- 2 cups (260 grams) powdered sugar
- pinch salt
Instructions
For the jam filling:
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In a large saucepan over medium heat, combine the rhubarb, sugar, lemon zest (reserve the lemon juice for later) and a pinch of salt.
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Cook, stirring occasionally, for 8–10 minutes until the mixture begins to boil and thicken.
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Cover, reduce the heat slightly, and simmer for about 10 minutes more, stirring now and then, until it thickens further.
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If it hasn’t thickened enough after 20 minutes, stir in 2 teaspoons cornstarch and simmer another 5 minutes—avoid overcooking, which can make the jam runny.
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Remove from heat and stir in the lemon juice. Transfer to a shallow container and chill until completely cool (about 2–3 hours).
For the cupcakes:
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Preheat oven to 350°F (175°C) and line a 12-cup muffin pan with liners.
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Whisk flour, sugar, baking powder and salt in a large bowl.
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In a separate bowl whisk milk, oil, vanilla, egg and hot water. Add the wet ingredients to the dry and stir until just combined. The batter will be thin—do not overmix.
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Fill each liner half full and bake 15–17 minutes until golden and a toothpick comes out clean. Cool completely on a rack before filling and frosting.
For the frosting:
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Beat the softened butter, vanilla, 1/2 cup rhubarb jam and a pinch of salt until smooth. On low speed, gradually add powdered sugar and beat until light and airy, about 3 minutes.
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Use a 1 teaspoon measure to remove a small plug of cake from each cupcake. Fill each hole with 1 teaspoon rhubarb jam and replace the cake plug.
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Pipe or spread the rhubarb buttercream over each cupcake. Store leftovers in an airtight container in the refrigerator for up to 3 days.