In a medium saucepan, combine granulated sugar, heavy cream, cocoa powder, butter, and salt. Stir over medium heat until the mixture comes to a boil.
Once boiling, reduce the heat to low and let it simmer for about 5 minutes, stirring constantly.
Remove the saucepan from heat and stir in the vanilla extract and chocolate chips until melted and smooth.
Pour the fudge mixture into a greased 8x8-inch square baking dish, spreading it evenly.
Allow the fudge to cool at room temperature for about 2 hours or until set.
Once set, cut the fudge into squares and dust with powdered sugar before serving.