Preheat the oven to 350 degrees Fahrenheit. Grease a 9×9-inch baking pan and line it with parchment paper.
Make the Brownies: In a large bowl, whisk the granulated sugar, brown sugar, and eggs until slightly thickened and pale. Slowly pour in the melted butter, followed by the vanilla, until smooth and well combined.
In a separate bowl, mix the flour, cocoa powder, espresso powder, baking powder, and salt.
Gradually add the dry mixture to the wet ingredients, stirring gently until about halfway combined. Add the chocolate chips and mix just until no streaks of flour remain.
Pour the batter into the prepared pan and spread it evenly. Bake for 25-30 minutes or until the edges are firm and the top is crackly. Let the brownies cool completely in the pan.
Make the Coconut Filling: In a medium bowl, whisk the sweetened condensed milk and powdered sugar until smooth. Stir in the coconut until well combined.
Spread the coconut mixture evenly over the cooled brownies. Pat gently to ensure a firm layer, and refrigerate for 15-20 minutes.
Make the Topping: In a medium saucepan over low heat (or microwave-safe bowl in 30-second intervals), heat the heavy cream and butter until hot but not scalding.
Remove the pot from the heat and add the chocolate chips. Stir well, then let sit for 3–4 minutes without stirring. Whisk well until smooth and glossy, and set aside to cool for 5 minutes.
Pour the chocolate topping over the coconut layer, spreading it evenly with a spatula. Set aside to cool for 30 minutes, then refrigerate for at least 1–2 hours to set completely.
Use the parchment paper to lift the dessert from the pan. Slice into squares and serve chilled or at room temperature. Enjoy!