Preheat your oven to 350°F (175°C). Melt 1/2 cup of unsalted butter and 3 oz. of bittersweet chocolate in a medium saucepan over low heat, stirring continuously until smooth. Stir in 1 cup sugar, followed by 2 large eggs, 1/2 cup flour, 1/2 tsp vanilla extract, and 1/4 tsp salt until well combined.

Grease an 8x8-inch baking pan and pour in the brownie batter. Bake for 25-30 minutes until a toothpick comes out with a few moist crumbs. Let cool on a wire rack.

Sprinkle 1 packet of gelatin in a bowl with 2 tbsp of cold heavy cream. Let sit for 5 minutes. In another bowl, combine 1 cup heavy cream, 1 cup dark chocolate chips, and 1/2 cup sugar. Heat gelatin until dissolved and mix into chocolate mixture, then whip until fluffy.

Spread the chocolate filling over the cooled brownie base evenly with a spatula.

Whip 1 cup heavy cream with 1/4 cup sugar and 1 tsp vanilla until stiff peaks form. Spoon over the chocolate filling evenly.

Cover with plastic wrap and refrigerate for at least 4 hours to set the filling.

Garnish with chocolate shavings or curls before serving.

Slice into squares and serve chilled.