Preheat oven to 350 °F (≈175 °C). Line a 9×13 inch baking pan with parchment paper, coat with nonstick spray; set aside.

In a large mixing bowl whisk together the melted butter, granulated sugar, and brown sugar until the sugar is mostly dissolved. Add the eggs and vanilla extract and whisk until smooth and combined.

Sift in the flour, cocoa powder, and salt. Stir until just combined (don’t overmix).

Spread the batter evenly into the prepared pan. Bake for about 25 to 30 minutes on the middle rack, until the brownies are just set and a toothpick inserted about 2 inches from the edge comes out clean (for fudgier texture avoid baking until completely dry). Then allow the brownies to cool completely in the pan on a wire rack.

For the coconut layer: once the brownie base is cooled, mix the shredded coconut, condensed milk, and powdered sugar in a large bowl until combined. Spread this evenly on top of the cooled brownies.

For the icing: In a medium saucepan over medium heat melt the butter, cocoa powder and milk together, stirring until smooth. Remove from heat and whisk in the powdered sugar until smooth and lump free.

Pour the icing over the coconut layer and spread gently to create an even top.

Allow the icing to set up (you may refrigerate briefly or let stand at room temperature) before cutting into squares.