Heat oven to 300 degrees. Whisk melted butter with vanilla. Toss brown sugar with cinnamon, allspice and nutmeg.
Toss popcorn with butter mixture. Sprinkle evenly with brown sugar mixture. Stir. Transfer to baking sheet lined with parchment paper.
Sprinkle apple chips and toffee bits over top. Bake 15 minutes, or until toffee bits start to melt. Cool before serving.
Tip: Add chopped pecans for extra crunch.