01 - Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper, leaving overhang on two sides for easy removal.
02 - In a large mixing bowl, whisk together the melted butter and granulated sugar until well combined. Add the eggs one at a time, beating after each addition, then stir in the vanilla extract until smooth.
03 - Fold in the cocoa powder, all-purpose flour, salt, and baking powder. Stir gently until just combined — do not overmix to keep the brownies fudgy.
04 - Spread the batter evenly into the prepared baking pan. Bake for 22 to 26 minutes, or until a toothpick inserted into the center comes out with moist crumbs. Allow to cool completely in the pan.
05 - While the brownies cool, spread the shredded coconut in an even layer on a baking sheet. Toast in the oven at 350°F for 5 to 7 minutes, stirring halfway through, until golden brown. Remove and set aside.
06 - Place the unwrapped caramel candies and milk in a microwave-safe bowl. Heat in 30-second intervals, stirring between each, until the caramel is fully melted and smooth.
07 - Stir the toasted coconut into the melted caramel until evenly coated. Spread the mixture in a uniform layer over the completely cooled brownies.
08 - Combine the chopped semi-sweet chocolate and coconut oil (if using) in a microwave-safe bowl. Microwave in 20-second intervals, stirring between each, until completely smooth and glossy.
09 - Drizzle the melted chocolate over the coconut-caramel layer in thin lines. Let the brownies set at room temperature, or refrigerate until the chocolate is firm. Lift from the pan using the parchment overhang, cut into 16 squares, and serve.