Add the walnuts, cacao powder, and salt to your food processor and blitz until they form a light crumb consistency. Add the dates and cashew butter blend further for a couple of minutes until the mixture starts to stick together to form a dough.
Line an 8x8" cake tin with parchment paper and press the brownie dough evenly into the base of the pan.
For the caramel, add all the ingredients to your high-speed blender and blitz until smooth and creamy without any lumps. Use a spatula to evenly spread the caramel over the brownie base (you can use all or just part of the caramel mixture if you prefer). Set aside in the fridge to chill.
Melt the chocolate and cashew butter and stir well. Pour the chocolate on top of the caramel brownies and use a spatula to spread it out evenly. Arrange the pecans on top of the chocolate while melted to ensure that they stick to it. Sit the brownies in the freezer for about 15 minutes to set.
Lastly, sprinkle with some sea salt for garnish and cut the brownies into 16 portions using a sharp knife.
Store these salted caramel walnut brownies in the fridge in order to keep them fresh as long as possible. Place them in an airtight container and they will keep for up to a week. You can freeze any leftover brownies and defrost them as needed. Make sure they are wrapped well or in an airtight container and freeze for up to a couple of months. Allow at least an hour to defrost them before serving.
Cashew butter: To keep these vegan brownies cashew-free, you can swap out the cashew butter for almond butter, peanut butter, hazelnut butter or tahini.
Walnuts: You can replace these with pecans if preferred.
Maple syrup: This can be substituted with agave syrup.