• Pre-heat your oven to 390℉/180℃. Line 12 muffin holes with cupcake/muffin liners.
• In a small bowl, break up the dark chocolate and melt in the microwave in 20 second intervals, stirring in between to make sure it doesn't burn. Alternatively, set up a double boiler. Do this by placing a heatproof bowl over a small pot of simmering water. Add the chocolate to the heatproof bowl and stir until melted.
• In a large mixing bowl, whisk together melted butter and both sugars. With an electric/stand mixer, go for a solid 3-5minutes so it is totally combined. Add in the eggs and vanilla and whisk.
• Now, add the melted chocolate slowly and combine once again. 
• Add the flour, cocoa powder and a pinch of salt – fold gently into the wet mixture with a rubber spatula or wooden spoon until just combined. Pour heaped tablespoons into each muffin cup. Don't be afraid to fill close to the top, they don't rise much.
• Bake 20-25 minutes until looking crinkly on top and with minimal wobble. While still warm, create indents in each brownie cup. Use a tablespoon measure, the end of a wooden spoon, an egg cup or anything else that works to press down the middle. Leave edges that stand tall, so there is a middle area we can fill with the liquid ganache.

For the Ganache Filling

• While these start to cool, make the ganache.
• Put the chocolate into a heatproof jug. If using a bar of solid chocolate, chop it into small pieces first.
• Heat the cream in a small saucepan over a low/medium flame. Keep stirring until the cream comes to the boil. Immediately turn off the heat and pour the cream into the bowl with the chocolate. Let rest 1 minute before stirring until the mixture comes together to form a glossy/rich consistency. While still liquid, pour into the wells you made in the brownie cups.
• Put the pan of brownie cups into the fridge to firm up (check the pan isn't still hot first, you don't want to damage your fridge shelves/other items in the fridge).
• Once the ganache has firmed up to your desired consistency, serve up! I leave these in the fridge and take them as and when we want some!