• Preheat the oven to 325°F (163°C) and line an 8-inch aluminum foil baking dish, leaving a two-inch overhang on both sides for easy removal.
• After lining, shake out any excess flour, then butter the foil and lightly dust it with flour.
• In a mixing bowl, whisk the eggs until they are smooth and slightly pale, which should take about 1 minute.
• Add the brown sugar, granulated sugar, and salt, whisking until everything is well combined. Stir in the vanilla extract.
• Sift the cocoa powder and flour over the mixture, then pour in the melted butter. Use a wooden spoon to stir until combined; the batter may be slightly lumpy.
• Pour the batter into the prepared baking dish, spreading it into an even layer.
• Bake in the preheated oven for approximately 40 minutes, or until a toothpick inserted into the center comes out with a thin layer of batter.
• Allow the cake to cool completely on a wire rack.

For the topping:

• Combine evaporated milk, egg yolks, brown sugar, and butter in a medium saucepan.
• Cook the mixture over medium heat, stirring constantly, until it thickens, which should take about 10 minutes.
• Remove the saucepan from the heat and stir in the vanilla extract. Then, mix in the shredded coconut and chopped pecans until well combined.
• Allow the mixture to cool for approximately 30 minutes at room temperature. Once cooled, spread it over the brownies. For cleaner cuts, cover and chill in the freezer for 15 minutes before slicing.
• Cut the brownies into squares just before serving.