Preheat the oven to 180°C/160°C fan/350°F/gas mark 4. Grease two 20cm/8in round cake tins and line with baking parchment.
Whisk together the milk, vinegar, sugar, oil and vanilla extract in a large jug.
In a large bowl sift together the plain flour, cocoa powder, baking powder, bicarbonate of soda, espresso powder and salt.
Gradually whisk the wet ingredients into the dry until the batter is smooth. It is important not to over-mix it however or the cake can become tough, so I recommend using a hand balloon whisk rather than an electric mixer.
Divide the batter evenly between the prepared tins (I use a scale for accuracy) and spread it level. Bake the cakes for about 30 minutes until they are firm to the touch and a skewer inserted into the centre comes out clean.
Leave the cakes to cool in the tins for 10 minutes then carefully turn them out onto a wire rack and leave to cool completely.
To make the filling, place the cornflour in a bowl and gradually stir in the coconut milk, making sure that there are no lumps.
Melt the butter and sugar together gently in a pan then whisk in the cornflour mixture. Bring the mixture up to a simmer and whisk constantly until it thickens.
Stir in the toasted pecans and coconut, vanilla extract and a pinch of salt. Set aside to cool.
To make the ganache, finely chop the chocolate and place it in a heat-proof bowl.
Place the coconut milk and maple syrup in a pan and heat until it is almost simmering. Do not let it come to the boil. Pour the hot milk over the chopped chocolate, making sure that it is fully covered, and leave to sit for five minutes.
Stir gently until melted and smooth. Set aside until it thickens enough to spread. If you accidentally leave it for too long and it sets, you can gently re-warm it in short bursts in the microwave, stirring often.
To assemble the cake, trim the tops of the cake layers with a cake wire or a sharp serrated knife to level them. Place one layer on a cake stand or plate and spread over all of the filling.
Place the other cake layer on top, upside-down. Spread over the ganache and decorate with chopped pecans if you like.