Preheat oven to 250°F. Line baking sheet with parchment paper (or silicone non-stick baking mat) and set aside.
Place 10 cups of popcorn in the largest bowl you have. Set aside remaining 6 cups of popcorn in another bowl.
In a heavy bottomed sauce pot, combine butter, brown sugar, corn syrup, molasses, salt and water. Set over medium heat to melt butter and sugar. Using a candy thermometer (or food safe thermometer), cook to 250°F. Stir mixture as needed to ensure even cooking.
Once desired temperature is reached, remove from heat. Add baking soda and vanilla and whisk to combine. (BE CAREFUL when adding baking soda, as caramel mixture will bubble up and rise!
Pour hot caramel over the 10 cups of popcorn. Using a large spatula, fold to distribute caramel among popcorn. Spread caramel popcorn into an even layer over prepared baking sheet. (If necessary, use more than one baking sheet if popcorn does not fit.) Bake for 60 minutes, stirring popcorn every 20 minutes to ensure even caramel coating.
Remove from oven and let popcorn mixture cool slightly. Break up any large chunks that may have formed
Combine caramel popcorn with reserved 6 cups of plain popcorn. Spread over a large baking sheet. Drizzle half of dark chocolate over popcorn. Follow by drizzling half of white chocolate. Sprinkle half of crushed candy canes. Let chocolate set.
Once chocolate has hardened, toss popcorn together. Spread into an even layer and drizzle remaining dark and white chocolate and crushed candy canes. Once chocolate is set, toss together. Store in an airtight container.