To make the brownie base, add the walnuts, salt, and cacao powder to your food processor and blend until the ingredients have broken down to a fine crumb consistency.
Add the dates and cashew butter and blend again for a couple of minutes until the mixture comes together to form a dough.
Line the bottom of an 11" x 7" pan (with a height of at least 2 inches) with parchment paper. You can also use an 8 x 8" pan.
Evenly distribute the brownie dough to the bottom of the pan and use a spatula or flat bottomed glass to smooth out and compress the dough into the base. Place in the freezer to set for 2 hours.
Meanwhile, prepare the caramel by adding the cashew butter, maple syrup, maca powder, and salt to a bowl.
Whisk the ingredients until they form a smooth caramel paste. Set aside.
Once the brownies are set, take the pan out of the freezer and add the caramel paste in a layer on top of the dough.
Use a spatula to gently smooth out the caramel as evenly as possible. Place the tray back in the freezer and allow the brownies to set for 4-6 hours (or overnight). Note: the caramel will not get completely hard, but you want it to set enough for you to be able to cut the brownies into portions.
Once set, remove the brownie slab from the tray and cut it into 16-20 portions, depending on what size you'd like to make them.
Once cut, transfer the brownies back onto a tray lined with parchment paper and set them back in the freezer until you're ready to garnish them. This will prevent them from getting too "melty" before you dip them in the chocolate!
Add the dark chocolate to a heat-resistant bowl and gently melt over a double boiler. Be sure not to overheat the chocolate, you just want it to get warm enough to melt.
Remove the brownies from the freezer and carefully dip them in the chocolate one by one. I sit them on a fork and spoon the chocolate over them to coat them evenly.
Place the brownies back on the parchment paper to set and garnish with some more sea salt.
These brownies are best stored frozen, and can be eaten straight from the freezer.