Step 1

Preheat the oven to 160 °C (fan). Grease and line a 20cm (7.8 inch) cake tin with baking parchment.

Step 2

In a medium bowl, whisk together the vegetable oil, plant milk, white wine vinegar, vanilla extract and light brown sugar. Whisk until smooth.

Step 3

In a separate small bowl, whisk together the boiling water and espresso powder until dissolved then add to the other wet ingredients and whisk to combine.

Step 4

In a separate medium bowl, sieve together the remaining dry cake ingredients. Add the wet ingredients mixture to the bowl and mix together until you just have a smooth batter.

Step 5

Transfer the batter to the prepared cake tin and place in the oven to bake for 15 minutes.

Step 6

Remove from the oven and leave to cool for 10 minutes on a wire cooling rack. Carefully remove the cake from the tin, remove the baking parchment and leave to cool fully on the wire cooling rack.

Step 7

Once cooled, return the cake to the cake tin and place in the fridge.

Step 8

Place the dark chocolate chips and plant milk in a microwaveable bowl. Heat in the microwave in 30 second bursts, whisking in between, until the chocolate and plant milk are melted together into a smooth glossy ganache. Set aside to cool for 10 minutes.

Step 9

Place the vegan whipping cream and sugar in the bowl of a stand mixer fitted with the whisk attachment. Alternatively place in a bowl if using hand-held electric beaters.

Step 10

Whip the vegan cream and sugar to the stiff peaks stage.

Step 11

Once the chocolate plant milk mixture is cooled, pour half into the whipped vegan cream and use a spatula to carefully fold it in until no pale streaks remain and it is uniformly brown. Repeat with the second half until completely combined.

Step 12

Spoon the chocolate mousse over the cake in the cake tin. Firmly tap the cake tin on the counter to remove any large air bubbles then smooth out the top with a spatula or pallet knife.

Step 13

Place the cake tin back in the fridge for 30 minutes.

Step 14

Place the dark chocolate chips and soy milk in a microwaveable bowl. Heat in the microwave in 30 second bursts, whisking in between, until the chocolate and soy milk are melted together into a smooth glossy ganache.

Step 15

Remove the cake from the fridge and pour the ganache over the top. Spread the ganache to the edges, if necessary, then place in the fridge to set fully for at least 3 hours before slicing and serving.