To make the bars:
Add the cashews and walnuts to a food processor. Pulse until ground. Add the cacao powder and sea salt. Pulse until combined. Transfer to a large bowl.
Add the dates, tahini paste, vanilla bean paste and coconut oil to the food processor. Process until a thick paste forms.
Add the date mixture to the large bowl with the nut mixture, and using your hands, mix until well combined. Add the cacao nibs and mix until fully incorporated.
Transfer the dough to an 8-inch square baking sheet lined with wax paper. Press the dough into the baking sheet until firm and evenly distributed. Put in the freezer while you make the frosting.
To make the frosting:
Add all ingredients to the food processor and process until smooth and creamy.
Spread the frosting over the protein bar mix using a small spatula and refrigerate for at least 3 hours before cutting.
These bars can be stored in the refrigerator, in an airtight container, for up to three days. This recipe was inspired by Lore Salas' Raw Brownie recipe.