Preheat the oven to 350°F (175°C). Line 8x8in (20x20cm) baking dish with parchment paper.
In a medium heatproof bowl, melt the chocolate and butter over simmering water until smooth.
Remove from heat, stir in the sugar. Cool slightly.
Add the eggs and vanilla extract and mix until well combined.
Stir in the flour and salt.
Add 2/3 of KitKat minis and mix until just combined. (Be careful not to over mix the batter, or the brownies will get dry and dense.)
Pour the batter into the prepared baking dish.
Bake for 20 minutes and check for doneness by inserting a toothpick in to the batter somewhere between the center and the edges of the brownies. If it comes out covered with batter, bake for another 2 minutes and check again. If the toothpick comes out slightly moist with a few crumbs, then it’s ready. It should take no longer than 25 minutes.
Cool completely on wire rack before removing from the pan. Cut into 16 squares and serve.
Notes
For step-by-step photos and additional notes, read the post above.