Preheat the oven to 350 F (176 C) and line a 9X9 inch baking pan with parchment paper, letting some overhang so that the brownies are easy to lift out of the pan after baked. Set aside.
In a medium sauce pan melt the butter and chocolate on medium low heat. Keep stirring until the chocolate has fully melted. Take off heat, and let cool for about 5-10 minutes. Alternatively you can melt the chocolate and butter together in a microwave safe bowl in 5 second bursts of heating, stirring between each 5 seconds of heating.
Stir in the granulated sugar and brown sugar until combine. Add one egg at a time, whisking in each before adding the next egg. Whisk in the vanilla extract.
Fold in the flour and salt. Gently stir until just combined. Do not over mix.
Pour half of the batter into the parchment lined baking pan, and then scatter the roughly chopped pieces of Bounty chocolate bars onto the batter. Pour over the remaining batter, making sure it is evenly spread.
Bake in oven for 35-36 minutes until a toothpick inserted comes out clean. Let cool completely, and then lift the brownies out of the pan. To get clean cuts, use a sharp knife and wipe it clean after each cut.