Spread the oats, hazelnuts, hemp hearts, and pepitas on a large baking sheet and cook until the oats are fragrant and the nuts and seeds lightly toasted, 8 minutes.
Transfer the toasted oats and seeds to a large bowl. Add the cocoa nibs, cocoa powder, and salt and stir well. Add the date mixture and stir until evenly mixed. Transfer to the prepared pan and use your hands to press the dough very firmly into the bottom, creating an even layer that fills the entire pan.
Put the chocolate chips into a small bowl and microwave on high in 30-second bursts, stirring after each one, until smooth, about 1 ½ minutes. Drizzle the chocolate over the top of the bars. Scatter 1 tablespoon hemp hearts over the bars. Freeze for 30 minutes.
Remove the pan from the freezer, run a knife around the edge and use the two draping sides of parchment to lift it from the pan. Cut into 12 bars or 16 bars, as desired. Store in a resealable bag or air-tight container and store in the fridge, where they will keep for several weeks.
Note: Cacao nibs are crushed cacao beans (or cocoa beans). If you don’t have cacao nibs, you can leave them out.