Preheat your oven to 350°F (175°C) and grease an 8x8-inch baking dish.

In a medium saucepan, combine the unsalted butter and semi-sweet chocolate chips over low heat. Stir until melted into a smooth mixture, about 5 minutes.

In a large mixing bowl, pour the cooled chocolate mixture and add granulated sugar. Whisk until fully combined, then add the eggs one at a time and the vanilla extract, whisking until smooth.

In a separate bowl, sift together all-purpose flour, cocoa powder, and salt. Mix to avoid lumps.

Fold the dry mixture into the wet ingredients gently until combined without overmixing.

Pour the brownie batter into the prepared baking dish and bake for 20–25 minutes. A toothpick should come out with a few moist crumbs when done.

Allow the brownies to cool completely, then frost with chocolate frosting and decorate creatively with chocolate chips and candies.