Step 1: Preheat your oven to 350°F (175°C). Prepare a 9x13-inch baking pan by greasing it or lining with parchment paper.

Step 2: In a medium mixing bowl, combine ½ cup of melted butter with 1 cup of granulated sugar and mix until smooth and glossy, about 2-3 minutes.

Step 3: Add 2 large eggs and 1 teaspoon of vanilla extract to the mixture and whisk until well incorporated.

Step 4: In a separate bowl, mix ½ cup of cocoa powder, ½ cup of all-purpose flour, ½ teaspoon of baking powder, and ¼ teaspoon of salt. Gradually fold this into the wet ingredients for about 1-2 minutes.

Step 5: Gently fold in ½ cup of mini chocolate chips evenly into the batter.

Step 6: Pour the brownie batter into the prepared pan and bake for 20-25 minutes. Check doneness with a toothpick.

Step 7: Allow the brownies to cool in the pan on a wire rack for 20-30 minutes before adding the topping.

Step 8: In a small saucepan, heat ½ cup of heavy cream, 2 tablespoons of butter, and 1 teaspoon of vanilla until melted and smooth, then mix in 1 cup of marshmallow fluff.

Step 9: Spread the marshmallow mixture over the cooled brownies and sprinkle with 1 cup of shredded coconut adding gentle pressure for adherence.

Step 10: Chill the brownies in the refrigerator for about 30 minutes to set the topping before slicing.