Melt the dark chocolate and butter in a microwave. It's best to microwave and stir in intervals until fully melted. Mix until fully incorporated.
In a separate bowl, add the eggs and lakanto monkfruit sweetener and beat well with a hand mixer for 3-4 minutes. Add the mascarpone cheese and mix for 1 minute then add the cocoa powder and mix for another 1 minute or until you have a smooth and creamy texture.
Pour in the dark chocolate and butter mixture to the brownie batter and mix well until thick and creamy.
You will need an 8x8 baking pan lined with parchment paper. Pour the batter inside and spread evenly across the pan using a spatula.
Place inside the oven and bake for 25 minutes.
Allow to cool for 10 minutes before cutting into slices.