Line a baking sheet with parchment paper. Arrange pitted dates in a close, even layer on the parchment.
Place a second sheet of parchment on top of the dates and use a rolling pin to roll and flatten them into a thin, even layer.
Remove the top parchment. Spread peanut butter evenly over the date layer.
Arrange thinly sliced apple evenly over the peanut butter.
Pour melted chocolate over the apple layer and spread evenly with a spatula.
Sprinkle pretzels over the chocolate and press down gently to adhere.
Freeze for at least 1 hour until completely firm. Cut or break into pieces and enjoy!