Preheat oven to 350 F. Line an 8x8 baking pan with parchment paper (or you can spray the pan with coconut oil).
Add the walnuts to the food processor and process until broken into very small pieces.
To a bare (medium or large) baking sheet, add the oats and the walnuts from the food processor (don’t clean the food processor yet). Use your hands to spread out and combine, then sprinkle with sea salt, if desired. Bake for 10-12 minutes or until slightly brown. Transfer to a bowl to cool slightly.
Meanwhile, to the food processor, add the dates, hemp seeds, acai powder, maple syrup, and vanilla. Blend until thoroughly combined.
Remove blade and using a spatula, transfer the acai mixture to a medium bowl. Note: it will be very sticky. Add the toasted oat/walnut mix to the bowl and combine with the acai mixture. Stir with a spoon until thoroughly combined. Fold in the chocolate chips and stir to combine.
Transfer the mixture to the 8x8 pan and press down evenly. Use a spatula to press down firmly. Then sprinkle the goji berries on top evenly and press down into the mixture, then add the coconut flakes, pressing down firmly. The more you press, the better the bars will hold together.
Freeze for 20 minutes to harden. When ready, remove by grabbing the edges of the parchment paper and transfer to a cutting board. Using a large knife, cut into 10 squares (1 1/2 inches wide).
Storage instructions: Keep refrigerated in an airtight container for up to 2 weeks or the freezer for 2 months. If frozen, thaw in the fridge overnight.