Step 1: Line a large baking sheet with parchment paper and set aside.
Step 2: In a small saucepan, combine sugar, water, and corn syrup. Heat over medium-high until the mixture reaches 300°F (hard crack stage). Pour onto a separate piece of parchment, spread thin, and let cool until hardened into ‘glass’.
Step 3: Melt the dark chocolate in a double boiler until completely smooth.
Step 4: Pour the melted dark chocolate onto the prepared baking sheet and spread into a thin, even layer using a spatula.
Step 5: Melt the white chocolate and stir in the red gel coloring until a deep blood-red color is achieved.
Step 6: Use a fork to splatter the red chocolate across the dark chocolate base in a dramatic fashion.
Step 7: Break the cooled sugar ‘glass’ into jagged shards and press them into the wet chocolate along with any other spooky decorations.
Step 8: Allow the bark to set completely at room temperature or in the fridge for 30 minutes before breaking into large pieces.