Line a baking sheet with parchment paper, ensuring it covers the entire surface.
In a microwave-safe bowl, melt the chocolate candy coating or almond bark according to package instructions, heating in 30-second increments, stirring in between, until fully melted and smooth.
In a separate mixing bowl, combine the creamy peanut butter, powdered sugar, melted butter, and vanilla extract (if using). Mix until well combined and smooth.
Pour half of the melted chocolate onto the prepared baking sheet, spreading it evenly. Dollop the peanut butter mixture on top and gently spread it over the chocolate without mixing the layers.
Drizzle the remaining melted chocolate over the peanut butter layer, spreading it evenly or creating a swirled effect.
Place the baking sheet in the refrigerator for about 1-2 hours, or until the chocolate is fully set. Once hardened, remove the bark from the pan and break it into pieces.
