- Heat an oven to 175ºC / fan 155ºC.
- Mix the sugar, butter, cacao powder, vanilla seeds and whisky in a pan and put it over a medium heat, until melted and combined. Let the mixture cool to room temperature.
- Mix flour, chopped chocolate, chopped nuts and salt in a bowl.
- Stir the flour mix into the cooled sugar mixture and add the eggs. Stir it with a whisk until it combines. Avoid further mixing!
- Pour the cake batter into a square 20cm baking tin lined with baking parchment. Bake the cake for 20-25 minutes, until the edges are firm, but the middle still soft. Let it cool completely before cutting.
- When serving: Whip the mascarpone together with the cream and whisky, until light and fluffy. Serve the brownies at room temperature with the cream and blueberries.