Soak raw walnuts overnight with a pinch of salt (or soak in hot water for 2 hours). Drain and rinse.
In a food processor, pulse together all the ingredients: raw walnuts, dates (pits removed)
Once the mixture is smooth and sticky, add cacao powder and blend again until well incorporated.
If the dough appears to be super wet, add in the pea protein or coconut flour.
Press the dough into an 8x8 or 9x5 pan.
In a microwave-safe bowl melt dark chocolate chips and coconut oil- and nut butter if using any
Pour the chocolate over the brownie layer. Sprinkle extra chopped walnuts and sea salt on top.
Place it in the fridge for at least an hour or freezer (half an hour) to allow the frosting to set before cutting.
Notes
If the batter appears to be too wet, you can add additional coconut flour or vegan pea protein powder, one tablespoon at a time. These 2 ingredients are both used to absorb additional moisture. So if you add too much of it, the batter might become too dry and grainy.