Soft Chocolate Traybake with Ganache

This Soft Chocolate Traybake is rich, moist, and deeply chocolatey, with a smooth ganache topping that makes it feel extra indulgent without being difficult to make. Greek yoghurt or sour cream keeps the sponge tender, while hot coffee intensifies the cocoa flavour without making the cake taste like coffee.

The finished cake is soft enough for an everyday bake but polished enough for birthdays, gatherings, or a simple dessert table. Once completely cool, it is topped with a silky chocolate ganache made from dark chocolate, milk chocolate, and cream.

Servings: 10-12 - Prep: 20 min - Cook: 30-35 min - Cooling: 1 hour - Total: About 1 hour 55 minutes

Ingredients

For the Cake

240 g plain flour (2 cups)
50 g unsweetened cocoa powder (½ cup)
200 g caster sugar (about 1 cup)
1½ tsp baking powder
1 tsp bicarbonate of soda
¼ tsp salt
2 large eggs, at room temperature
180 g full-fat Greek yoghurt or sour cream (¾ cup)
120 ml neutral oil (½ cup)
1 tsp vanilla extract
150 ml freshly made hot coffee or hot water (⅔ cup)

For the Chocolate Ganache

100 g dark chocolate, 70% cocoa (3.5 oz)
120 g milk chocolate (4.2 oz)
100 g double cream or heavy cream (about ⅓ cup + 1 tbsp)

Instructions

1. Prepare the Tin and Oven

Preheat the oven to 175°C conventional / 155°C fan / 350°F. Grease a 28 x 17 x 5 cm baking tray. Line the base and long sides with baking paper, leaving enough overhang to help lift the cake out after baking.

2. Mix the Dry Ingredients

Sift the flour and cocoa powder into a medium bowl. Add the baking powder, bicarbonate of soda, and salt. Whisk thoroughly until the mixture is evenly coloured and no cocoa lumps remain.

3. Mix the Wet Ingredients

In a large bowl, whisk the eggs and caster sugar for about 60 seconds, until slightly lighter and glossy. Add the Greek yoghurt or sour cream, neutral oil, and vanilla extract. Whisk gently until smooth and well combined.

4. Combine the Batter

Add the dry ingredients in two batches. Fold gently after each addition. When only a few streaks of flour remain, pour in the hot coffee or hot water in two additions. Whisk slowly just until the batter becomes smooth. The batter should be loose and pourable.

5. Bake

Pour the batter into the prepared tray and level the surface. Tap the tray once gently on the worktop to release any large air pockets. Bake for 30-35 minutes, or until the centre springs back lightly when touched and a skewer inserted into the middle comes out with a few moist crumbs but no wet batter.

6. Cool Completely

Leave the cake in the tray for 15 minutes. Lift it out using the baking paper, remove the paper, and place the cake on a wire rack. Allow it to cool completely before adding the ganache. Do not assemble the cake while it is even slightly warm, as the ganache may melt and slide off.

Chocolate Ganache

You can prepare the ganache using either the microwave method or the bain-marie method.

Microwave Method

Finely chop the dark chocolate and milk chocolate and place them in a microwave-safe bowl.
Pour the cold double cream over the chocolate.
Microwave for 20 seconds at medium power
Remove and stir gently from the centre outward.
Return to the microwave in 10-15 second bursts, stirring well after each one.
Stop heating as soon as most of the chocolate has melted.
Continue stirring until the ganache becomes completely smooth and glossy.

Avoid overheating, as this can cause the ganache to split.

Bain-Marie Method

Finely chop the dark chocolate and milk chocolate and place them in a heatproof bowl.
Pour the cold double cream over the chocolate.
Place the bowl over a saucepan containing a small amount of gently simmering water.
Make sure the bottom of the bowl does not touch the water.
Heat gently, stirring occasionally, until most of the chocolate has melted.
Remove the bowl from the heat and continue stirring until the ganache is smooth and glossy.

7. Let the Ganache Thicken Slightly

Leave the ganache at room temperature for 10-20 minutes, stirring occasionally. It should become slightly thicker but still spread easily. If it becomes too firm, warm it very gently for a few seconds.

8. Top the Cake

Place the completely cooled cake on a serving board or plate. Pour or spoon the ganache over the top. Spread it evenly with an offset spatula or the back of a spoon.

9. Set and Slice

Allow the ganache to set slightly before slicing. Cut into squares or rectangles using a sharp knife. For cleaner slices, wipe the knife between cuts.

Tips and Tricks

✅ Use room-temperature eggs and yoghurt so the batter combines smoothly.

✅ Sift the cocoa powder to remove lumps and create a more even chocolate sponge.

✅ Hot coffee deepens the chocolate flavour but does not make the cake taste strongly of coffee.

✅ If you prefer, use hot water instead of coffee.

✅ Do not overmix once the flour is added, as this can make the cake dense.

✅ The batter should look loose and pourable before baking.

✅ Let the cake cool fully before adding ganache.

✅ Chop the chocolate finely so it melts evenly and quickly.

✅ Heat the ganache gently. Overheating can make it oily or cause it to split.

✅ Mixing dark and milk chocolate gives a balanced ganache that is rich but not too bitter.

✅ Let the ganache cool slightly before spreading so it sits neatly on top instead of running down the sides.