Delicious Rhubarb Cake with Butter Sauce

This Delicious Rhubarb Cake with Butter Sauce is a quintessential springtime dessert that perfectly balances tart fruit with a sweet, buttery crumb. It is incredibly easy to prepare and features a decadent warm sauce that elevates the cake to a gourmet level. Whether you are hosting a garden party or looking for a comforting family treat, this recipe is sure to become a seasonal favorite.

Why You Will Love This Recipe

There are so many reasons to fall in love with this Delicious Rhubarb Cake with Butter Sauce. First, the texture is exceptionally moist, thanks to the way the rhubarb breaks down during the baking process. Second, the flavor profile is a sophisticated mix of tangy and sweet that appeals to both children and adults. Finally, the homemade butter sauce is a total game-changer, soaking into the warm cake to create a rich, melt-in-your-mouth experience that store-bought desserts simply cannot replicate.

Ingredients

• 2 cups all-purpose flour
• 1 1/4 cups granulated sugar
• 1/2 cup unsalted butter, softened
• 1 cup whole milk
• 1 large egg
• 2 teaspoons baking powder
• 1/2 teaspoon salt
• 3 cups fresh rhubarb, chopped into 1/2-inch pieces
• 1 cup granulated sugar (for the sauce)
• 1/2 cup unsalted butter (for the sauce)
• 1 cup heavy whipping cream (for the sauce)
• 1 teaspoon pure vanilla extract (for the sauce)

Step-by-Step Instructions

1. Preheat your oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan or a similar sized casserole dish to ensure the cake does not stick.
2. In a large mixing bowl, cream together the softened butter and 1 1/4 cups of sugar until the mixture is light and fluffy.
3. Add the egg and beat well until fully incorporated.
4. In a separate medium bowl, whisk together the all-purpose flour, baking powder, and salt.
5. Gradually add the dry ingredients to the creamed mixture, alternating with the milk. Start and end with the flour mixture, mixing just until combined after each addition.
6. Gently fold in the chopped rhubarb using a spatula, ensuring the fruit is evenly distributed throughout the batter.
7. Spread the batter evenly into the prepared baking pan. Bake for 40 to 45 minutes, or until a toothpick inserted into the center comes out clean.
8. While the cake is baking, prepare the butter sauce. In a medium saucepan, combine the sugar, butter, and heavy cream.
9. Bring the sauce mixture to a gentle boil over medium heat, stirring constantly. Let it boil for exactly one minute, then remove from heat and stir in the vanilla extract.
10. Allow the cake to cool slightly, then slice and serve warm with a generous drizzle of the hot butter sauce.

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Expert Tips / Pro Tips

To get the best results with your Delicious Rhubarb Cake with Butter Sauce, always use fresh, firm rhubarb stalks. If your rhubarb is particularly thick, slice the stalks lengthwise before chopping them into pieces to ensure they soften properly while baking. Another tip is to avoid overmixing the batter once you add the flour; overmixing can lead to a tough, dense cake. For the sauce, make sure you use real heavy cream rather than milk to achieve that signature velvety consistency that makes this dish so special.

Variations & Substitutions

If you find yourself short on rhubarb, you can substitute half of the amount with fresh sliced strawberries for a classic strawberry-rhubarb twist. For those who prefer a bit of spice, adding a teaspoon of ground cinnamon to the dry ingredients provides a lovely warmth. If you need a dairy-free version, you can substitute the butter with a plant-based butter alternative and use full-fat coconut milk in place of the heavy cream for the sauce, though the flavor profile will shift slightly toward coconut.

Serving Suggestions

While this cake is incredible on its own with the butter sauce, you can take it to the next level by serving it with a scoop of high-quality vanilla bean ice cream. The cold ice cream melting into the warm sauce creates a wonderful contrast. A dollop of lightly sweetened whipped cream or a sprinkle of fresh mint leaves also makes for a beautiful presentation if you are serving this at a formal dinner or brunch.

Storage, Freezing & Reheating

Store any leftover cake in an airtight container at room temperature for up to two days, or in the refrigerator for up to five days. The butter sauce should be stored separately in a glass jar in the refrigerator. To reheat, place a slice of cake in the microwave for 15-20 seconds and warm the sauce separately until it becomes liquid again. This cake also freezes well; wrap individual slices tightly in plastic wrap and foil, and freeze for up to three months. Thaw in the fridge overnight before reheating.

Nutrition Information

FAQ

Do I need to peel the rhubarb before using it?

No, you do not need to peel rhubarb for this recipe. The skin softens significantly during the baking process and provides the beautiful pink flecks seen throughout the cake.

Can I use frozen rhubarb for this cake?

Yes, you can use frozen rhubarb. However, make sure to thaw it completely and drain all excess liquid before folding it into the batter to prevent the cake from becoming too soggy.

Why did my butter sauce crystallize?

Crystallization usually happens if the sugar isn’t fully dissolved or if the sauce is boiled for too long. Ensure you stir constantly and only boil for one minute as instructed.

Is rhubarb safe to eat raw?

The stalks of the rhubarb are safe to eat raw or cooked, but you must always discard the leaves, as they contain high levels of oxalic acid and are toxic.

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Delicious Rhubarb Cake with Butter Sauce

A moist, tender cake packed with tart rhubarb, topped with a rich, velvety warm butter sauce that makes it truly irresistible.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 45 minutes mins

Total Time 1 hour hr 5 minutes mins

Servings: 12 slices

Course: Dessert

Cuisine: American

Calories: 420

Ingredients Method Notes

Ingredients

  

Cake Ingredients

• 1/2 cup (113g) (softened) butter
• 1 1/4 cups (250g) granulated sugar
• 1 large egg
• 1 cup (240g) sour cream
• 2 cups (250g) all-purpose flour
• 1 tsp baking soda
• 1/2 tsp salt
• 3 cups (chopped) fresh rhubarb

Butter Sauce

• 1/2 cup (113g) butter
• 1 cup (200g) granulated sugar
• 3/4 cup (180ml) heavy cream
• 1 tsp vanilla extract

Method

 

Instructions

1. Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking pan with butter or non-stick cooking spray.
2. In a large mixing bowl, cream together the softened butter and 1 1/4 cups of sugar until the mixture is light and fluffy.
3. Beat in the egg and the sour cream until the mixture is smooth and well combined.
4. In a separate bowl, whisk together the flour, baking soda, and salt; gradually add these dry ingredients to the wet mixture until just combined.
5. Gently fold in the chopped rhubarb using a spatula, ensuring it is evenly distributed throughout the thick batter.
6. Spread the batter evenly into the prepared baking pan and bake for 40 to 45 minutes, or until a toothpick inserted in the center comes out clean.
7. While the cake is baking, prepare the sauce by combining the butter, sugar, and heavy cream in a small saucepan over medium heat.
8. Bring the sauce to a boil and cook for 2 minutes, stirring constantly, then remove from heat and stir in the vanilla extract.
9. Serve the cake warm, cutting into squares and drizzling each portion generously with the warm butter sauce.

Notes

For the best texture, use fresh rhubarb. If using frozen rhubarb, thaw and drain it thoroughly before adding to the batter to prevent excess moisture.