Soak walnuts in enough water to cover them overnight to soften. This process of soaking nuts and seeds is called‘sprouting’. Rinse, drain and set aside to dry off any residual moisture in strainer.
Line a square pan with 2 strips of parchment paper, criss crossed so it covers all 4 sides of pan.
Using a food processor, pulse and finely grind nuts.
Add dates and pulse a few times until dates are broken up.
Add in remaining ingredients and process to form paste. This will eventually form into a ball in the processor.
Transfer to lined pan. Press to create uniform layer with back of spoon. Cover, store in fridge until frosting is made.
For the Frosting, heat milk in small saucepot over medium until steaming.
Place chopped chocolate in a medium sized bowl. Pour over hot milk and sprinkle in sea salt and let sit for 3 minutes. The heat from the milk will be enough to melt the chocolate.
Whisk until smooth. Frost brownies and place back in fridge for ganache to set, about 2-3 hours. Cut into small squares and serve. Brownies are best stored in the fridge and freeze well.