Line a baking sheet with parchment paper and set aside
Melt the semi-sweet chocolate on the stove or in the microwave, stirring frequently, until all of the chocolate is melted and smooth
Pour the melted chocolate onto the lined baking sheet, and spread into a thin and even layer with a spatula.*
Melt the white chocolate on the stove or in the microwave, stirring frequently, until all of the chocolate is melted and smooth
Pour the melted white chocolate over the semi-sweet chocolate layer. You can either pour it in stripes, or gently spread it into somewhat of an even layer over the semi-sweet chocolate (it does not need to be evenly distributed or fully covering the semi-sweet layer as you will be swirling it)
Swirl by gently running a butter knife back and forth through the chocolate to create swirls. You can do this in a zig-zagging pattern, or swirl freely, to create the design you like!
Evenly distribute Halloween m&ms and Halloween sprinkles across the top of your chocolate bark
Place your pan on a flat surface in your fridge to harden
Once set, cut or break your bark into the size pieces you’d like, serve, and enjoy!
Store chocolate bark in the fridge in an air-tight container for up to 3 weeks (if it lasts that long!)