Step 1: Prepare the Baking Tin
Preheat your oven to 180°C (160°C fan), Gas Mark 4.
Lightly spray a 22cm square baking tin with low-calorie cooking spray and line the base with baking parchment.
Step 2: Whisk the Egg Yolks
Place the egg yolks in a large mixing bowl with the granulated sweetener and vanilla extract.
Using an electric hand whisk, beat for approximately 4–5 minutes until the mixture becomes pale, thick and airy.
Step 3: Whip the Egg Whites
In a separate clean, dry bowl, whisk the egg whites until they form soft peaks.
Gently fold the whipped egg whites into the egg yolk mixture using a spatula, taking care not to knock out too much air.
Step 4: Add the Dry Ingredients
Sift the self-raising flour and baking powder together.
Gradually fold the flour mixture into the eggs until just combined.
Avoid overmixing, as this can make the sponge dense rather than light and fluffy.
Step 5: Bake Until Golden
Pour the mixture into your prepared tin and gently level the surface.
Bake for 20–25 minutes, or until the sponge is golden, springy to the touch and a skewer inserted into the centre comes out clean.
Leave the cake in the tin for 10 minutes before transferring it to a wire rack to cool completely.
Step 6: Prepare the Creamy Vanilla Icing
Combine the thick Greek yoghurt, quark, sifted icing sugar and vanilla extract in a bowl.
Stir until smooth and creamy.
Refrigerate for 15–20 minutes to help the mixture firm up slightly.
Step 7: Decorate the Cake
Once the sponge has cooled completely, spread the creamy vanilla topping evenly across the surface.
Scatter the colourful sprinkles over the icing.
Place in the fridge for a further 15–20 minutes before slicing into 16 squares.
Serve chilled and enjoy!
Tips for the Best Light and Fluffy Sponge
Use room-temperature eggs. They whisk more easily and help create a lighter sponge.
Choose a baking-friendly sweetener. Different sweeteners have different levels of sweetness and bulk, so follow the manufacturer’s conversion guidance.
Fold gently. Keeping as much air as possible in the egg mixture helps the cake rise.
Don’t overbake. Check the sponge after 20 minutes to prevent it from becoming dry.
Cool completely before icing. A warm sponge will cause the yoghurt topping to soften and slide off.
Use thick yoghurt. A strained Greek-style yoghurt works best for a creamy topping that holds its shape.
Delicious Variations to Try
Lemon Vanilla Traybake
Add finely grated lemon zest to the sponge and a little lemon juice to the topping for a refreshing citrus twist.
Strawberry Vanilla Cake
Replace the sprinkles with chopped fresh strawberries just before serving.
Chocolate Chip Vanilla Traybake
Fold a small handful of mini chocolate chips into the sponge before baking. This will increase the calories per serving.
Birthday Cake Traybake
Use pastel-coloured sprinkles and a little extra vanilla extract for a fun celebration cake.
How to Store Vanilla Traybake
Because the topping contains fresh dairy ingredients, keep the decorated cake in an airtight container in the fridge for up to 3 days.
For the best texture, store the sponge and topping separately if preparing ahead.
The uniced sponge can also be frozen for up to 2 months. Wrap it tightly, defrost at room temperature and decorate before serving.
Frequently Asked Questions
Can I make this vanilla traybake without butter?
Yes! This recipe uses whipped eggs to create a light sponge without added butter or oil.
Can I use plain flour instead of self-raising flour?
Yes, although you’ll need to adjust the raising agents. For 150g plain flour, use approximately 2 tsp baking powder in total.
Why is my vanilla sponge dense?
Overmixing the batter or deflating the whipped egg whites can make the sponge heavy. Fold the ingredients together gently and bake promptly.
Can I make the icing without quark?
Absolutely. Replace the quark with the same quantity of thick, fat-free Greek yoghurt. The topping may be slightly softer.
Does the icing set like traditional icing?
No. This yoghurt-based topping stays creamy and soft rather than forming a firm sugar glaze. Keep the cake chilled until serving.
Is this vanilla traybake suitable for meal preparation?
Yes. You can bake the sponge a day ahead and store it in an airtight container. Add the fresh topping shortly before serving for the best results.
Final Thoughts
This low calorie vanilla traybake is a simple way to enjoy a classic homemade cake with a lighter twist.
Its airy vanilla sponge, creamy topping and colourful sprinkles make it a lovely dessert for sharing with family and friends.
Whether you’re planning afternoon tea, preparing a weekend treat or looking for an easy lower-fat cake recipe, this vanilla traybake is well worth trying.
