Chocolate Passionfruit Gateau

Chocolate Passionfruit Gateau

My Instagram is filled with giant 4-5 layered cakes and huge milkshakes where I wonder how it’s still standing and how you are supposed to eat it. Visually impressive but I’m a simple girl at heart (FYI my favourite flavour is vanilla). This chocolate passionfruit gateau is less impressive visually – bland brown colour with only 1 layer but looks are always deceiving. This recipe is adapted from Heston Blumenthal (the master of deception) and I think he made it look so simple and plain so that whoever eats it gets a popping surprise.

A poprock biscuit base for an exploding surprise is where it all starts. The base is made like a cheesecake base so it doesn’t really matter if you use chocolate ripple biscuits or shortbread (as in the original recipe). The hero component is the rich ganache top with a subtle passionfruit flavour; if you’ve ever had nama chocolate it’s the same soft, smooth texture. The weird thing is that when you try the ganache just after it’s made (at step 11 below), it tastes pretty weird from the passionfruit flavour. That’s why I recommend leaving it in the fridge overnight (and not for 2 hours as the original recipe) as it not only let’s the ganache set but also develops the flavour. After an overnight wait, get ready for this cake to literally poprock your world ;)

Chocolate Passionfruit Gateau

Recipe adapted from Heston’s Exploding Chocolate Gateau

Makes one 15cm cake




150g chocolate ripple biscuits or shortbread biscuits

40g unsalted butter

2 tbsp white caster sugar

25g neutral poprocks


Chocolate ganache

175g thickened cream

pinch of salt

Pulp from 6 passionfruits (about 185g if using pulp from a can)

50g fresh custard (I use Paul’s custard)

110g dark chocolate (min 60%), broken into pieces

50g milk chocolate, broken into pieces



Cocoa powder




  1. Line the base and sides of a 15cm cake tin.
  2. Process chocolate ripple biscuits until it has a fine sand texture.
  3. Transfer to a mixing bowl and mix in butter and caster sugar.
  4. Wait until biscuit mixture is cooled then gently stir in poprocks (don’t overstir or they’ll start popping more).
  5. Place mixture into cake tin and flatten with the back of the spoon until surface is level. Place to one side to let it set.
  6. In a small saucepan, add cream, salt and passionfruit.
  7. Place this over medium heat and wait until it nearly comes to boil.
  8. Remove saucepan from heat and let it stand for 5 minutes.
  9. Stir custard into the saucepan.
  10. Melt chocolate by placing dark and milk chocolate in a heat proof bowl over a bain marie (saucepan of simmering water). Once melted, take bowl full of chocolate away from heat.
  11. Strain the infused cream and add to the bowl of melted chocolate, one-third at a time, making sure to incorporate the cream thoroughly after each addition. Allow ganache to cool to room temperature.
  12. Once tart base is set, use a pastry brush to spread some of the ganache on the top of the base and around the edges, then place in freezer for 5 mins (will prevent ganache seeping through).
  13. After 5 minutes, pour the rest of the ganache into the cake tin and place in the fridge (covered with cling wrap) to set overnight.
  14. When ready to serve, sprinkle cocoa powder on top of cake.
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