Melt chocolate and spread in a single layer on a parchment paper-lined baking sheet.
Top with pretzels in a single layer
In a small saucepan, whisk together cashew butter and maple syrup over low heat until combined. Stir in diced apples at the end and pour over pretzels. Optional: melt extra chocolate to drizzle on top at this step.
Transfer to the freezer & freeze until set, about 1 hour.