Add the pistachios, maple syrup, and salt to a large food processor. Process on high until smooth - depending on the strength of your food processor, this may take around 10 minutes. The pistachios will first turn into a fine crumb, then into a large ball, and then become a smooth butter. If you need to, stop your food processor to scrape down the sides and let the machine cool down every few minutes.
Optional: once smooth, add the olive oil to the pistachio butter and process again until smooth and cohesive. This will yield a smoother, more drippy pistachio butter. Set aside.
Line a baking sheet with parchment paper. Slice dates in half and spread them on the baking sheet, making sure they overlap each other slightly so that there’s no empty space. Arrange them into 4 to 5 rows.
Add another piece of parchment paper on top of the dates and use the bottom of a glass to flatten the dates and firmly press them together.
Spread the pistachio butter evenly on top of the dates (you may have extra! Store it in an airtight container in the fridge).
Add the chocolate chips to a bowl with the coconut oil. Microwave on high for 2 minutes, stirring halfway through, until melted.
Pour the chocolate on top of the pistachio butter and spread until even and smooth. Top with crushed pistachios and salt and place in the freezer for at least 1 hour to harden.
Using a knife, cut the date bark into pieces and serve.