Preheat oven to 160°C and butter a 20cm square glass cake pan. In a small saucepan, melt the butter. Place the chopped chocolate disks into a mixing bowl and, when the butter is just below the boil, pour it over the chocolate and let stand for 30 seconds. Then stir until chocolate is completely melted.
Sift in the sugar and cocoa powder. With a wooden spoon, beat in the mascarpone, eggs and Staffords Vanilla Extract, mixing until smooth. Gently fold the flour and salt into the batter, and pour into prepared pan and spread evenly. (This is very important: if the batter isn’t spread evenly, it won’t bake evenly.)
Place into the preheated oven and bake for 45-50 minutes, or until a tester comes out clean. Place pan on a cooling rack and let brownies cool for 10-15 minutes – or put into the fridge to speed the process – while you make the ganache.
For the ganache, place chopped chocolate disks into a mixing bowl. In a small saucepan, over medium heat, bring the cream and butter to just below boiling point and pour mixture over the chocolate. Let stand for 30 seconds and then stir until smooth. Spread over the brownies while it’s still warm. When the ganache has firmed, cut the brownies.
Decorate with a Staffords White Chocolate disk placed on top of the ganache and a berry of your choice.