The Best Rhubarb and Custard Cake (Easy Traybake Recipe!)

A Delicious Taste of Nostalgia

Some flavour combinations are like time machines, instantly transporting you back to a cherished memory with a single bite. For me, that magical pairing has always been rhubarb and custard. The sharp, tangy rhubarb balanced by sweet, creamy custard is the taste of pure comfort, of cozy afternoons and simple, heartfelt desserts. I recently had a powerful craving for that specific nostalgic flavour, which led me to create this perfect rhubarb and custard cake. It’s a wonderfully moist almond and custard-infused sponge, studded with jewels of tart rhubarb and dotted with pockets of even more creamy custard. It’s an easy, shareable traybake that captures a classic combination in every single bite.

The Simple Ingredients for a Perfect Traybake

This cake cleverly uses custard in two ways—custard powder in the batter for flavour and colour, and ready-made custard swirled throughout for creamy pockets of deliciousness.

Ingredient	Quantity	Notes
Fresh Rhubarb	300g	Look for firm, crisp stalks. This will be chopped into small pieces.
Soft Unsalted Butter	225g	Use room temperature butter for a light, fluffy cake batter.
Caster Sugar (Superfine Sugar)	175g	Dissolves easily for a smooth, even crumb.
Large Eggs	3	Should be at room temperature to prevent the batter from curdling.
Self-Raising Flour	200g	The leavening is already included, making the cake light and airy.
Custard Powder	45g	Adds a lovely vanilla flavour and golden colour to the sponge.
Ground Almonds (Almond Flour)	90g	The secret to an incredibly moist and tender cake.
Ready-Made Custard	200g	A brilliant shortcut for creating creamy pockets throughout the cake.

this now & bake later ❤️

Timing Breakdown

This impressive-looking cake is surprisingly quick to put together, making it perfect for an afternoon baking project.

• Preparation Time: 15 minutes
• Cook Time: 45 minutes
• Cooling Time: 20-30 minutes
• Total Time: Approximately 1 hour 20 minutes

Data Insight: This delightful traybake is ready in about 80 minutes. By using ready-made custard as a clever shortcut, you save at least 20-30 minutes of prep time compared to making a traditional crème pâtissière from scratch, all while achieving that authentic, creamy custard flavour.

Step-by-Step Instructions

Step 1: Prepare Your Pan and Rhubarb

First, preheat your oven to 350∘F (180∘C / 160∘C Fan / Gas Mark 4). Thoroughly grease a 9×9-inch (23cm) square baking tin and line the base with parchment paper. Prepare your rhubarb by washing it well, trimming the ends, and slicing the stalks into small, 1cm (about 21​-inch) pieces. Set aside.

Step 2: Create the Luscious Cake Batter

In the bowl of a stand mixer or in a large bowl with a handheld electric mixer, beat the softened butter and caster sugar together for several minutes until the mixture is very pale, light, and fluffy. This step incorporates air, which is key to a tender cake. Add the eggs one at a time, beating well after each addition.

Step 3: Combine the Dry Ingredients and Custard

In a separate bowl, whisk together the self-raising flour, custard powder, and ground almonds. Add this dry mixture to the wet ingredients and mix on a low speed until just combined. Pro Tip: Be careful not to overmix at this stage. Finally, pour in half (100g) of the ready-made custard and mix again until it is fully incorporated into the smooth, golden batter.

Step 4: Fold in the Rhubarb and Assemble

Gently fold most of the chopped rhubarb into the cake batter, saving a small handful to sprinkle on top. Scrape the batter into your prepared tin and use a spatula to level the surface. Sprinkle the reserved rhubarb pieces over the top.

Step 5: Add the Custard Pockets and Bake

Now for the magic part! Take the remaining 100g of ready-made custard. Using a teaspoon, drop dollops of the custard randomly over the surface of the cake batter. You can use the back of the spoon to make slight indents for the custard to sit in. Place the tin in the preheated oven and bake for 45 minutes, or until the cake is golden brown, risen, and a skewer inserted into the sponge part of the cake comes out clean.

Step 6: Cool and Serve

Let the cake cool in the tin on a wire rack for at least 20-30 minutes before slicing. This is important as it allows the custard pockets to set properly. Serve warm or at room temperature.

Nutritional Information

Here is an approximate nutritional breakdown per slice, assuming the traybake is cut into 12 squares.

• Calories: Approx. 390 kcal
• Fat: 22g
• Carbohydrates: 42g
• Sugar: 25g
• Protein: 7g

Disclaimer: Nutrition is estimated and can vary based on specific brands and portion sizes.

Variations and Dietary Needs

This comforting cake is easy to adapt to your specific needs.

• Gluten-Free: Simply substitute the self-raising flour with a high-quality gluten-free self-raising flour blend. The ground almonds already make this cake wonderfully suitable for a GF conversion.
• Dairy-Free: Use a good quality block-style plant-based butter and a dairy-free ready-made custard (often made with soy or oats, and available in many supermarkets).
• Different Fruit: This cake base is also fantastic with other tart fruits. Try it with chopped cooking apples, gooseberries, or plums.
• Lower Sugar: You can reduce the caster sugar in the batter by about 25g-50g if your rhubarb is young and less tart, or if you prefer a less sweet cake.

Serving Suggestions

This rhubarb and custard traybake is a complete treat on its own but can be elevated even further.

• The “Double Custard” Experience: This is my personal favourite! Serve a warm slice of the cake with a generous pour of extra warm custard over the top.
• With a Cup of Tea: It’s the perfect cake for a classic afternoon tea.
• A La Mode: A scoop of high-quality vanilla bean or clotted cream ice cream is a wonderful contrast to the warm, tangy cake.
• Simple and Elegant: For a simple finish, a light dusting of powdered sugar over the cooled cake looks beautiful.

Common Mistakes to Avoid

1. A Curdled Batter: This often happens when cold eggs are added to the creamed butter and sugar mixture, causing the butter to seize up. Using all room-temperature ingredients is the best way to ensure a smooth, stable batter.
2. Over-mixing the Batter: Once you add the flour, mix only until the last streaks disappear. Over-mixing develops the gluten in the flour, which can lead to a tough, heavy cake.
3. All the Rhubarb Sinks: Rhubarb pieces are heavy and can sink to the bottom. To help prevent this, you can toss the chopped rhubarb in one tablespoon of the measured flour before gently folding it into the finished batter.
4. Slicing While Too Warm: It’s incredibly tempting to cut into this cake straight from the oven, but you must let it cool. This allows the custard pockets to firm up. If you slice it while it’s piping hot, the custard will be runny and the slices will be messy.

Storing Your Traybake Cake

This cake is incredibly moist and stores very well.

• Storage: Once completely cool, store the cake in an airtight container at room temperature for up to 3 days. If your kitchen is very warm, it’s best to store it in the refrigerator for up to 5 days.
• Serving from the Fridge: If refrigerated, allow slices to come to room temperature or gently warm them in the microwave for 15-20 seconds before serving for the best flavour and texture.
• Freezing: This cake freezes beautifully. Cut it into individual squares and wrap them well in plastic wrap and foil. Freeze for up to 3 months. Thaw at room temperature.

A Classic Combination in a Perfect Cake

This rhubarb and custard cake is the ultimate comfort bake. The wonderfully moist almond sponge is the perfect vehicle for the tart rhubarb pieces and the creamy, sweet pockets of custard. It’s a simple, rustic, and shareable traybake that brings a beloved, nostalgic flavour combination to life in a new and exciting way. It is guaranteed to be a hit at any family gathering, bake sale, or afternoon tea.

We truly hope you enjoy this taste of nostalgia! Let us know how it turned out by leaving a comment and a rating below. Be sure to subscribe for more comforting and delicious baking recipes!

FAQs

Q1: What is custard powder? Can I substitute it?

Custard powder is a cornstarch-based powder, usually coloured yellow and flavoured with vanilla. It’s a popular pantry staple in the UK for making quick, easy custard. If you can’t find it, you can substitute it with an equal amount of cornstarch and 1 teaspoon of vanilla extract.

Q2: Can I use frozen rhubarb in this cake?

Yes, you can use frozen rhubarb. There’s no need to thaw it first. Simply chop the frozen stalks and fold them into the batter as you would with fresh rhubarb. You may need to add 5-10 minutes to the baking time.

Q3: My rhubarb sank to the bottom of the cake. How can I prevent this?

A great trick to prevent fruit from sinking is to toss it in a tablespoon of flour before folding it into the batter. This helps the fruit “grip” the batter and stay more suspended. Also, be sure not to cut your rhubarb pieces too large.

Q4: Can I make this as a round cake instead of a traybake?

Yes. This recipe will work perfectly in a 9-inch (23cm) round springform cake tin. The baking time should be roughly the same, but it’s always best to check with a skewer to be sure.

Q5: Does this cake need to be refrigerated?

Because of the pockets of ready-made custard, it’s best to store this cake in the refrigerator if it’s not going to be eaten within a day or two, or if your kitchen is particularly warm. It will keep for up to 5 days in the fridge.

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