Line a small baking sheet or large plate with parchment paper or wax paper.
Remove the pits from all the medjool dates. If you have pre-pitted dates, this step is quicker.
Open each date down the center and gently pull apart the sides so the date can lay flat. Place the dates on the lined parchment paper, creating the first layer of the Snickers bark. Repeat with all the dates, arranging them in a single layer.
Place another sheet of parchment paper on top of the dates. Using your hand or the bottom of a cup, press down to flatten the dates into a single layer, filling in any gaps between them.
In a microwave-safe bowl, heat the chocolate and coconut oil (if using) in 30-second increments, stirring between each increment. Repeat 2-3 times until the chocolate is fully melted. Set aside momentarily.
Spread the peanut butter evenly over the flattened dates.
Drizzle the melted chocolate over the peanut butter layer. Use a spoon, flexible spatula, or icing knife to spread the chocolate evenly.
Sprinkle the chopped peanuts and a pinch of flaky salt over the chocolate layer.
Transfer the Snickers date bark to the fridge for 1 hour or the freezer for 20-30 minutes to chill and set.
Once the bark is set, remove it from the fridge or freezer and use a sharp knife to cut it into your desired number and size of pieces.
This healthy Snickers candy bark is best enjoyed straight from the fridge.