Tangy Rhubarb Custard Cake

This rhubarb custard cake transforms tangy spring stalks into a dessert that perfectly balances sweet and tart flavors. The cake features three distinct layers that meld together during baking: a tender vanilla cake base, tart pieces of rhubarb, and a creamy custard topping that creates a magical texture combination.

I first made this cake when my neighbor gifted me with a huge bundle of garden rhubarb. Now it has become our traditional spring celebration dessert that signals the start of warmer days ahead.

Ingredients

• All purpose flour: creates a tender crumb while providing structure
• Baking powder and baking soda: work together for the perfect rise
• Granulated sugar: balances the tartness of the rhubarb
• Eggs: bind the batter while adding richness
• Vegetable oil: keeps the cake moist for days
• Vanilla extract: enhances the flavor of both cake and custard
• Milk: creates a tender texture in the cake layer
• Fresh rhubarb: provides bright color and tangy flavor
• Custard powder: creates the magical creamy layer on top

Step-by-Step Instructions

Preheat the Oven:

Set your oven to 175°C and thoroughly grease and flour a 9inch round cake pan. This preparation step ensures your cake will release perfectly after baking. A springform pan works particularly well if you have one available.

Mix Dry Ingredients:

Combine flour, baking powder, baking soda, and salt in a medium bowl with a whisk. This aerates the dry ingredients and distributes the leavening agents evenly. Proper distribution prevents uneven rising during baking.

Prepare Wet Ingredients:

In a large bowl, beat sugar, eggs, vegetable oil, and vanilla extract until the mixture becomes pale and slightly thickened. This incorporates air into the batter for a lighter texture. Add milk and stir until completely incorporated.

Combine the Batter:

Carefully fold the dry ingredients into the wet mixture using a spatula with gentle strokes. Stop mixing as soon as no dry spots remain. Overmixing activates gluten which can make your cake tough instead of tender.

Add Rhubarb:

Gently fold in the chopped rhubarb pieces until evenly distributed throughout the batter. The rhubarb will rise slightly during baking, so an even distribution ensures balanced flavor in every slice.

Prepare the Custard:

In a saucepan, whisk milk, custard powder, and sugar over medium heat. Stir constantly to prevent lumps and scorching. Continue cooking until the mixture thickens enough to coat the back of a spoon but remains pourable.

Layer the Cake:

Pour the cake batter into your prepared pan and smooth the top with a spatula. Next, carefully pour the warm custard over the cake batter. Use the back of a spoon to create gentle swirls between the layers.

Bake the Cake:

Place in the preheated oven and bake for 35 to 40 minutes. The cake is ready when the top turns golden brown and feels set but slightly jiggly in the center. The custard will continue to set as it cools.

Cool and Serve:

Let the cake rest in the pan for at least 15 minutes before attempting to slice. This allows the custard to set properly. Serve warm or at room temperature with a dollop of whipped cream for the perfect contrast.

Save

The custard layer is truly what makes this cake special in my family. My grandmother taught me that the secret is to pour the custard when it is warm but not hot, creating that magical melding of cake and custard that defines this recipe.

The Rhubarb Factor

Rhubarb is the star of this cake with its bright pink color and distinctive tang. When selecting rhubarb, look for firm stalks with vibrant color. The redder the stalks, the sweeter the flavor. Avoid any stalks that appear limp or have soft spots. Remember that rhubarb leaves contain oxalic acid and should never be used in cooking.

Storage and Make Ahead Tips

This cake actually improves after sitting for a day as the flavors meld together. Store covered at room temperature for up to 24 hours or refrigerate for up to 3 days. To serve after refrigeration, let the cake come to room temperature or warm individual slices briefly in the microwave for about 15 seconds to restore the soft texture.

Seasonal Variations

While traditional rhubarb season runs from April through June, this versatile cake can be adapted for other seasons. In summer, replace rhubarb with sliced peaches or berries. Fall calls for thinly sliced apples tossed with cinnamon. Winter variations work beautifully with poached pears or cranberries. The custard layer complements all these fruits equally well.

Serving Suggestions

This cake exists in the delightful space between casual and elegant. For a simple family dessert, serve slices on their own. For entertaining, dress it up with a dollop of whipped cream, a scoop of vanilla ice cream, or a drizzle of warm custard sauce. For brunch, pair with fresh berries and a sprig of mint for a colorful presentation.

Recipe FAQs

→ Can I use frozen rhubarb instead of fresh?

Yes, frozen rhubarb works perfectly fine. Just make sure to thaw it completely and drain any excess liquid before adding it to your batter. This prevents the cake from becoming too wet during baking.

→ What can I substitute for custard powder?

Vanilla pudding mix is the best direct substitute for custard powder. Alternatively, you can make a homemade custard using egg yolks, sugar, cornstarch, milk and vanilla extract if you prefer avoiding packaged mixes.

→ How do I store leftover cake?

Store leftover cake in an airtight container in the refrigerator for up to 3 days. The custard layer makes refrigeration necessary. Allow it to come to room temperature before serving, or gently warm individual slices in the microwave for 15-20 seconds.

→ Can I make this dairy-free?

Yes, you can make a dairy-free version by substituting the milk with almond milk or another plant-based alternative. Just ensure your custard powder doesn't contain dairy ingredients, and the cake should turn out equally delicious.

→ How do I know when the cake is fully baked?

The cake is done when the top is golden brown and a toothpick inserted into the center comes out clean. The custard layer should be set but might still have a slight jiggle. The total baking time is typically 35-40 minutes at 175°C (350°F).

→ What other fruits work well in this cake?

While rhubarb provides that signature tartness, this cake base works beautifully with other fruits. Try strawberries (classic with rhubarb), apples, plums, or peaches. Each will bring its own character to the dessert while maintaining the lovely contrast with the custard layer.