TO PREPARE THE CHOCOLATE BROWNIE BASE:
Pre-heat oven t0 180°C (160°C for a fan oven) / 350°F / Gas Mark 4. Grease the sides and base of a 18cm x 18cm square tin and line with baking paper.
Whisk 2 eggs in a bowl and set aside.
Empty the brownie mix into a separate, larger bowl, and add the whisked egg, 95ml of oil and 45ml of water. Fold together gently with a spoon until well mixed.
Place the mixture into the baking tin and spread out with the back of a spoon.
Bake for 25 – 30 minutes or until a skewer inserted 5cm from the edge of the brownie comes out almost clean.
Allow to cool before transferring to a large serving plate.
TO PREPARE THE CHOCOLATE MOUSSE TOPPING:
Empty the sachet of chocolate mousse into a mixing bowl and add 150ml of milk. If you are feeling like a particularly indulgent dessert, replace the milk with double cream!
Whisk on high speed for 3 minutes until thick and creamy, then spoon over the top of the brownie, gently smoothing the top with a round bladed knife.
Top with raspberries and a light dusting of icing sugar, and serve.
If not serving immediately, store in the refrigerator and eat within 2 days.