Preheat oven to 350 degrees F. Grease an 8x8 inch baking pan and line with parchment paper with plenty of overhang.
Add chopped chocolate to a medium bowl and set aside.
In a small saucepan over medium-high heat, add butter and ¼ cup granulated sugar, cook until butter is melted and sugar has mostly dissolved around 2 minutes.
Remove from heat and immediately pour over chopped chocolate. Leave to rest for few minutes then whisk vigorously until smooth. Set aside and allow to cool slightly.
In a small bowl mix all-purpose flour, cocoa powder, and salt.
Add the eggs, brown sugar, remaining granulated sugar, and vanilla in a large mixing bowl. Using electric mixer mix until foamy and pale in color, 5 to 7 minutes. It should almost double its volume and sugar has to be dissolved (rub mixture between your fingers to see if sugar is dissolved).
Pour in the slightly cooled chocolate mixture and mix until smooth.
Using a rubber spatula, gradually stir dry ingredients into wet until just combined.
Fold in cherries and chopped chocolate.
Transfer the batter to the prepared pan, and smooth the top with a spatula.
Bake for 35 to 40 minutes or until the top of the brownies is set and shiny, with few cracks in the surface. The center of the brownies will seem under baked and the toothpick inserted in the middle will not be clean.
Allow brownies to cool completely in the pan.
Use the parchment paper to lift the cooled brownies out of the pan. Cut into 9 to 16 bars and serve.