Prep baking sheet: Line your baking sheet with parchment paper and set aside.
Remove pits from dates: Use a butter knife to slice each date lengthwise and remove the pit. Repeat on all dates.
Place dates on parchment paper: Open each date, and press it down firmly on the parchment paper, with the inside facing down. Repeat until all dates are on the parchment, closely touching each other. I like to arrange them in five rows with three dates each, so it forms a rectangle.
Flatten dates: Cover the dates with another piece of parchment paper, and press down firmly to flatten. You can do this with a rolling pin, the flat bottom of a glass, or your hands. You're aiming for a thin and even layer.
Add peanut butter: Remove the top piece of parchment paper. Spread peanut butter over dates, reaching the edges.
Melt chocolate: Meanwhile, melt your chocolate with coconut oil. You can do this in the microwave in 15-second intervals, or on the stove over low heat. Stir frequently to prevent burning your chocolate.
Spread chocolate: Pour melted chocolate over dates. Spread to the edges.
Add toppings: Immediately top with crushed peanuts and a generous pinch of flakey salt.
Freeze: Transfer to the freezer for 30-60 minutes.
Slice: Working quickly, peel the parchment off the back of the date bark. You should be left with one large slice. Transfer to a cutting board and slice into squares. Keep stored in a container in the freezer. Enjoy!