Rhubarb Cake with Butter Sauce

This tangy rhubarb cake with warm butter sauce transforms a humble garden stalk into a dessert worthy of special occasions. The sweet butter sauce creates the perfect balance with the naturally tart rhubarb, making each bite a delightful contrast of flavors and textures.

I discovered this recipe during the first spring in our new home when the rhubarb patch in the backyard was bursting with stalks. After trying several rhubarb recipes, this cake became our family favorite and now signals the official start of spring in our household.

• All purpose flour forms the sturdy base for our cake while still keeping it tender
• Baking powder gives the perfect rise without being too airy
• Salt enhances all the flavors and balances sweetness
• Granulated sugar tames the rhubarb tartness perfectly
• Unsalted butter adds richness in both cake and sauce
• Egg provides structure and richness
• Vanilla extract adds warmth and depth to both components
• Milk creates a tender crumb
• Fresh rhubarb brings bright tartness and beautiful pink flecks
• Heavy cream creates an irresistibly silky butter sauce

How To Make Rhubarb Cake with Butter Sauce

Prepare your equipment

Preheat your oven to 350°F and thoroughly grease a 9inch square baking pan, making sure to get into the corners where sticking is most likely to occur.

Mix dry ingredients

Whisk together flour, baking powder, and salt in a medium bowl until evenly distributed. This ensures even rising and prevents flour pockets in the final cake.

Cream butter mixture

In a large bowl, beat the sugar and softened butter for at least 3 minutes until noticeably lighter in color and fluffy in texture. This incorporates air for a lighter cake. Add egg and vanilla, beating until completely combined and smooth.

Combine wet and dry ingredients

Add the flour mixture to your butter mixture in three portions, alternating with milk additions. Begin and end with flour. Mix just until combined after each addition. Overmixing will develop gluten and make your cake tough.

Fold in rhubarb

Gently fold in the chopped rhubarb pieces using a rubber spatula with a light hand. Aim for even distribution throughout the batter without crushing the rhubarb pieces.

Bake the cake

Transfer the batter to your prepared pan and spread evenly to the corners. Bake for 45 to 50 minutes, checking with a toothpick inserted in the center. It should come out with a few moist crumbs but no wet batter.

Prepare butter sauce

While the cake bakes, combine butter, sugar, and heavy cream in a medium saucepan over medium heat. Stir constantly until the sugar completely dissolves and the mixture is smooth and slightly thickened, about 5 minutes. Remove from heat and stir in vanilla extract.

Serve warm

Let the cake cool for about 10 minutes before cutting. Drizzle each serving with warm butter sauce, allowing it to soak slightly into the cake before serving.

The rhubarb in this cake is truly what makes it special. I grow several varieties in my garden, but for this recipe, I prefer the vibrant red stalks that give tiny pink bursts throughout the cake. My grandmother always said the redder the rhubarb, the sweeter the cake, and though that's not technically accurate, the sentiment makes me smile every time I bake this.

Selecting The Best Rhubarb

When shopping for rhubarb, look for firm, crisp stalks with shiny skin. The color can range from pale green to deep red, but avoid any with wilted leaves or brown spots. Thinner stalks are typically more tender and require less cooking time. Remember to discard the leaves, as they contain high levels of oxalic acid and are not edible.

Make Ahead And Storage Tips

This cake can be made a day ahead and stored at room temperature in an airtight container. The butter sauce should be stored separately in the refrigerator and gently reheated before serving. For longer storage, freeze individual cake slices in airtight containers for up to 3 months. Thaw at room temperature and warm slightly before serving with freshly heated sauce.

Seasonal Variations

While traditional rhubarb shines in this recipe, you can adapt it throughout the year. In summer, try substituting half the rhubarb with strawberries for a classic flavor combination. Fall brings opportunities for apple rhubarb combinations, and in winter, using frozen rhubarb works beautifully. Just thaw and drain excess moisture before folding into the batter.

Serving Suggestions

This versatile cake works equally well as a homey dessert or an elegant finish to a dinner party. For casual gatherings, serve warm with a scoop of vanilla ice cream alongside the butter sauce. For more formal occasions, plate individual slices with a drizzle of sauce, fresh berries, and a sprig of mint. You can also serve this as a decadent breakfast cake with morning coffee.

Recipe FAQs

→ Can I use frozen rhubarb instead of fresh?

Yes, frozen rhubarb works well in this cake. Thaw it completely and drain excess liquid before folding into the batter. You may need to increase the baking time by 5-10 minutes as frozen rhubarb tends to release more moisture during baking.

→ Can I make the butter sauce ahead of time?

Absolutely! The butter sauce can be made up to 3 days ahead and stored in an airtight container in the refrigerator. Gently reheat on the stovetop or microwave until warm before serving with the cake.

→ How do I store leftover cake?

Store leftover cake in an airtight container in the refrigerator for up to 3 days. Store the butter sauce separately. Reheat individual slices in the microwave for 15-20 seconds before topping with warmed sauce.

→ Can I substitute the rhubarb with other fruits?

Yes, strawberries, apples, or peaches make excellent substitutes for rhubarb in this cake. Keep the same quantity (2 cups) and be aware that sweeter fruits may make the final result sweeter than with tart rhubarb.

→ Why is my cake too moist or undercooked in the center?

Rhubarb releases moisture during baking, which can affect the cake's texture. Ensure your rhubarb isn't overly wet when adding to the batter. If the cake browns too quickly but remains underbaked, cover loosely with foil during the last 15 minutes of baking time.

→ Can I make this cake in a different size pan?

Yes, this cake can be made in a 9-inch round pan or an 8x8-inch square pan. Adjust baking time as needed - test with a toothpick for doneness. For a larger batch, double the recipe and use a 9x13-inch baking dish, increasing baking time by 10-15 minutes.