Chocolate Brownie Cake

Method

1. Whip the eggs with the sugar for at least 10 minutes until the mixture is light and fluffy. In the meantime, melt the finely chopped dark chocolate in the microwave (at 600 Watt one minute at a time) or in a bain-marie. Melt the butter, then add the seeds inside half of a vanilla bean and mix it with the dark chocolate, obtaining a smooth and shiny mixture, then let it cool.
2. Add the chocolate and butter mixture to the egg and sugar mixture, mix well, then combine them, while sifting the flour and baking soda together and add them to the mixture. Now add the coarsely chopped walnuts and salt.
3. Coat the bowl with the butter and flour, transfer the mixture to the bowl, and close with its lid. Pour the water into the pressure cooker (indicate how much), insert the bowl with the special support, and close the pressure cooker. Turn on the heat to high: as soon as the pot is pressurized, turn it back down to low and let it cook for about 40 minutes. After cooking, turn off the heat and put the valve on the vent; once all the steam has come out, open the pressure cooker and remove the bowl, take off its lid and let it cool.
4. Take out the cake, place it upside down on the dish you have selected and garnish it with melted dark chocolate and a few chopped walnuts.