Preheat the oven to 170 °C. Grease and line a 20x20cm (8x8 inch) square cake/brownie tin.
Place the plant milk, vegan yoghurt, vegetable oil, vanilla extract and white wine vinegar in a medium bowl and whisk until smooth. Set aside.
140 ml plant milk, 75 g vegan yoghurt, 50 ml vegetable oil, 1 teaspoon vanilla extract, 1 ¼ teaspoon white wine vinegar
In a large bowl, sieve then whisk together the cake flour, sugar, baking powder, baking soda and salt.
180 g cake flour, 125 g caster sugar, 1 ½ teaspoon baking powder, ¼ teaspoon baking soda, ¼ teaspoon fine sea salt
Add the wet ingredients to the dry and stir until just smooth. Don’t over mix.
Pour the batter into the prepared tin and bake for 25 minutes.
Remove from the oven and allow the cake to cool for 10 mins in the tin on a wire cooling rack before carefully flipping and leaving to cool fully.
While the cake cools, prepare the soak.
To Make the Soak
In a medium bowl, whisk together the soak ingredients. If the condensed milk doesn’t whisk smooth, heat the mixture in the microwave for 20 seconds or until gently warmed then whisk again.
180 ml vegan evaporated milk, 90 ml vegan sweetened condensed milk, 30 ml plant milk, ½ teaspoon vanilla extract
Return the cooled cake to the cake tin and prick all over with a fork. Pour the soak over the entire cake, then cover and leave to soak for at least 3 hours, ideally overnight.
To Make the Whipped Cream Layer
Place the vegan whipping cream in the bowl of a stand mixer fitted with the whisk attachment and beat on high speed until soft peaks form. Alternatively, whip the vegan cream in a medium bowl using an electric hand whisk. Add the caster sugar and vanilla extract then whip again until stiff peaks form.