Preheat the oven to 350°F (175°C).
Grease an 8x8-inch baking pan.
Melt the butter and chocolate together in a large bowl.
Mix in the sugar and allow it to cool slightly.
Add the eggs one at a time, then stir in the vanilla.
Sift together the cocoa powder, flour, and salt, then fold it into the wet mixture.
Stir in the chopped leftover candy.
Pour the batter into the prepared pan and spread it evenly.
Bake for 20-25 minutes or until a toothpick comes out with moist crumbs.
Allow the brownies to cool before cutting into squares.
