01 - Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving an overhang on two sides for easy removal.
02 - In a large mixing bowl, whisk melted butter and granulated sugar until well combined. Add the eggs one at a time, beating after each addition until smooth. Stir in the vanilla extract. Fold in the cocoa powder, all-purpose flour, salt, and baking powder until just incorporated — do not overmix.
03 - Pour the batter into the prepared pan and spread it into an even layer. Bake for 22 to 26 minutes, or until a toothpick inserted into the center comes out with moist crumbs attached. Allow the brownies to cool completely in the pan on a wire rack.
04 - While the brownies cool, spread the shredded coconut evenly on a rimmed baking sheet. Toast in the 350°F oven for 5 to 7 minutes, stirring halfway through, until the coconut is golden brown. Remove and set aside to cool.
05 - Place the unwrapped caramel candies and milk (or cream) in a microwave-safe bowl. Heat in 30-second intervals, stirring between each, until the caramels are fully melted and the mixture is smooth and pourable.
06 - Fold the toasted coconut into the melted caramel until evenly coated. Spread the coconut-caramel mixture in an even layer over the cooled brownie base, pressing gently to adhere.
07 - Combine the chopped semi-sweet chocolate and coconut oil (if using) in a microwave-safe bowl. Melt in 20-second intervals, stirring between each, until the chocolate is completely smooth and glossy.
08 - Drizzle the melted chocolate over the coconut-caramel layer in a decorative pattern. Let the brownies set at room temperature, or refrigerate for 30 minutes until the chocolate firms up.
09 - Using the parchment overhang, lift the brownies out of the pan. Cut into 16 even squares with a sharp knife. Serve at room temperature for the best texture.