Chubby Hubby - Salted caramel, dark chocolate brownies

Ingredients

• 115g unsalted butter
• 150g dark chocolate (I use 70% cocoa)
• 1 tsp instant coffee
• 2 tbsp cocoa powder
• ½ cup sugar
• ¼ cup light brown sugar
• 1 tsp vanilla extract
• 3 eggs
• ¾ cup plain flour, sifted
• ½ tsp coarse salt
• ¾ cup sugar
• 6 tbsp (90g) butter, cubed
• ½ cup heavy cream
• 1 tsp coarse sea salt