Spread the 10 cups of popped popcorn on a large, parchment-lined baking sheet (or two smaller sheets). Pick out any unpopped kernels so no one bites into a hard piece.
10 cups popped popcorn
Place the candy canes or peppermint candies in a zip-top bag. Seal the bag, then gently hit it with a rolling pin or the bottom of a heavy pan until you have a mix of small pieces and fine peppermint dust. Set aside.
3/4–1 cup crushed candy canes or peppermint candies
Add the white chocolate and about 2 teaspoons of the neutral oil to a microwave-safe bowl. Microwave in 20–30 second bursts, stirring well after each, until completely smooth and melted, about 1–1 1/2 minutes total. If the mixture seems thick or lumpy, stir in another teaspoon of oil until silky.
8 ounces white chocolate, 1 tablespoon neutral oil
Stir the peppermint extract and fine sea salt into the warm white chocolate. Taste a tiny bit and, if desired, add another drop or two of peppermint extract for a stronger flavor, being careful not to overdo it.
1/2 teaspoon peppermint extract, 1/4 teaspoon fine sea salt
Pour the peppermint white chocolate mixture over the popcorn. Using a large spatula or clean hands, gently toss until the popcorn is as evenly coated as possible. Work fairly quickly before the chocolate starts to set.
10 cups popped popcorn, 8 ounces white chocolate, 1 tablespoon neutral oil, 1/2 teaspoon peppermint extract, 1/4 teaspoon fine sea salt
While the coating is still wet, sprinkle the crushed candy canes all over the popcorn. Toss very lightly so the pieces stick without forming one large clump, unless you prefer big clusters.
3/4–1 cup crushed candy canes or peppermint candies
In a clean microwave-safe bowl, combine the semi-sweet or dark chocolate with the remaining neutral oil. Microwave in short 20–30 second bursts, stirring between each, until smooth and pourable.
4 ounces semi-sweet or dark chocolate, 1 tablespoon neutral oil
Use a spoon or transfer the melted dark chocolate to a small sandwich bag and snip a tiny corner. Drizzle the chocolate over the peppermint-coated popcorn in zigzag lines to create a peppermint bark look. Add holiday sprinkles or mini chocolate chips now, if using.
4 ounces semi-sweet or dark chocolate, holiday sprinkles, mini chocolate chips, additional melted chocolate
Leave the tray at room temperature for 15–20 minutes, or until the chocolate is firm to the touch. If your kitchen is warm, place the tray in the refrigerator for about 10 minutes to help it set.
Once the chocolate is fully set, break the peppermint bark popcorn into clusters. Transfer to a serving bowl, or portion into jars, treat bags, or tins for gifting.