Heat oven to 180C/350F/Gas Mark 4.
Grease a tin with vegetable oil of your choice and add a little flour to a 20cm square tin.
Prepare your flaxseed mix by combining your ground flaxseed with 6 tablespoons of water. Leave to rest for 5-10 minutes.
In a saucepan, melt 120g chocolate, coffee and your water on a low heat. Allow to cool slightly.
Put the flour, almonds, cocoa, baking powder (if using) and ¼ tsp salt in a bowl and stir to remove any lumps.
Using a hand whisk, mix the sugar into the melted chocolate mixture. Beat well until smooth and glossy until the sugar is dissolved.
Stir in your flaxseed mixture, vanilla extract and remaining 80g of chocolate. Fold in your Leon vegan mayo.
Sieve the flour mixture into the bowl gradually, folding it in.
Spoon into the prepared tin and bake for 20-25 minutes until a skewer inserted in the middle comes out clean with moist crumbs.
Allow to cool in the tin completely, then cut into squares.
Serve with a scoop of coconut ice-cream or dollop of coconut yogurt.