Line a baking sheet with parchment or wax paper to create a clean surface for cooling your bark cookies. Crush the peppermint bark Oreos into bite-sized chunks (you want pieces substantial enough to dip, not powder), and measure out your crushed peppermint candies for garnish. Having everything prepped and ready before you start melting chocolate ensures a smooth, efficient process.

Melt the white chocolate using a double boiler or microwave in 30-second intervals, stirring between each interval to ensure smooth, even melting without scorching. Once fully melted and silky, immediately stir in the peppermint extract until completely incorporated. I find that adding the extract right after melting helps the flavor distribute evenly throughout the chocolate without any concentration in certain spots.

Working quickly while the chocolate is still warm, dip each crushed Oreo chunk into the peppermint white chocolate mixture, coating it thoroughly on all sides. Use a fork or dipping tool to help submerge and remove each piece, allowing excess chocolate to drip back into the bowl. Immediately place each dipped cookie onto your prepared parchment paper, spacing them slightly apart so they don't touch while cooling.

While the chocolate coating is still wet and tacky, sprinkle crushed peppermint candies generously over each cookie piece—this is your window to garnish, as once the chocolate sets, the candy won't stick. Let the cookies cool at room temperature for 20-30 minutes until the chocolate is completely hardened, or speed up the process by refrigerating for 10-15 minutes. I like to let them set at room temperature first since it gives a nicer texture than rushed chilling.