To make the brownies:

Place chocolate and butter in a large heat-proof bowl, and microwave in 30 second-intervals, stirring in between each interval, until melted. Alternatively, set the bowl over a saucepan of simmering water, stirring occasionally, until melted, then remove from heat. Add the sugar and whisk until combined. Add the eggs, one at a time, and whisk just until combined. Add flour and salt and fold, using a rubber spatula, stir just until combined. Do not overmix. Pour batter into prepared pan, and smooth the top. Bake for 15-18 minutes until the edges are set but center is still soft, and a toothpick inserted into the center of the brownies come out with moist crumbs, and not dry. Let the brownies cool for 10 minuted on a wire rack, before adding the coconut layer.

Meanwhile, make the coconut layer:

Mix all the ingredients in a large bowl until well combined. Spread evenly into the pan, on top of the brownie layer. Bake for 8-10 minutes until set. It should stay bright in color. Allow to cool completely on a wire rack.

To make the chocolate ganache:

Place chocolate and cream in a medium heat-proof bowl, and microwave in 20-30 second-intervals, stirring in between each interval, until melted. Alternatively, set the bowl over a saucepan of simmering water, stirring occasionally, until melted. Pour ganache evenly over the brownies. Place in the fridge for at least 4 hours until completely set, then cut into squares. The brownies keep well for several days in the fridge in an airtight container.