Preheat your oven to 350°F (175°C) and prepare a 9x13 inch baking pan by greasing it or lining with parchment paper.

Melt 0.5 cups of unsalted butter in a medium mixing bowl and stir in 1 cup of granulated sugar until creamy.

Add 2 large eggs and 1 teaspoon of vanilla extract; whisk until fully combined and slightly frothy.

Sift in 0.33 cups of cocoa powder, 0.5 cups of all-purpose flour, 0.5 teaspoon of baking powder, and 0.25 teaspoon of salt; fold until just combined.

Fold in 0.5 cups of mini chocolate chips until evenly distributed.

Pour brownie batter into the prepared pan and spread evenly. Bake for 20-25 minutes, until a toothpick comes out with a few moist crumbs.

Allow the brownies to cool in the pan on a wire rack for about 30 minutes.

In a saucepan, combine 0.5 cups of heavy cream, 2 tablespoons of butter, and 1 teaspoon of vanilla extract. Heat until melted and combined.

Stir in 1 cup of marshmallow fluff until smooth, allowing it to cool slightly until spreadable.

Spread the marshmallow mixture evenly over the cooled brownies and sprinkle 1 cup of shredded coconut on top, pressing it down gently.

Refrigerate for about 30 minutes to set the layers before slicing and serving.