Line a baking sheet with parchment paper or a silicone mat to prepare for spreading the chocolate.
Melt the dark chocolate in a microwave-safe bowl using short bursts, stirring in between, until smooth and glossy.
Pour the melted dark chocolate onto the prepared sheet and spread it evenly with a spatula to about 1/4-inch thickness, creating a smooth, shiny surface.
Repeat melting the white chocolate in the microwave, stirring until fully smooth. If desired, add a few drops of food coloring to tint the white chocolate with a spooky hue.
Drizzle the melted white chocolate over the dark layer in a swirling pattern, creating a marbled effect for an eerie look.
Add your spooky toppings—sprinkles, candy eyes, crushed cookies, and edible glitter—while the chocolate is still warm and slightly tacky, pressing lightly to help them stick.
Let the bark cool at room temperature for 1-2 hours until fully set. For quicker results, place it in the fridge for about 30 minutes.
Once cooled and firm, break the large sheet into rustic shards using clean hands or a sharp knife for a jagged, spooky appearance.
Enjoy your festive Halloween bark, perfect for sharing at parties or as a spooky sweet treat!