Place the popped popcorn in a large bowl and salt to taste (skip this step if you have salted popcorn). Set aside.
Mix the honey and sugar in a small saucepan and bring to a boil. Let it simmer for about 2 minutes, then remove from the heat and add the peanut butter. Stir vigorously until all the peanut butter is melted, then mix in the vanilla extract.
Immediately pour the peanut butter caramel over the popcorn and gently stir with a long-handled wooden spoon until it's all coated. Spread popcorn on a large baking sheet over a piece of wax or parchment paper. Drizzle popcorn with melted chocolate and let sit until chocolate hardens (I stuck it in the freezer for a couple of minutes to speed it along). Stir in the Mini Reese's Peanut Butter Cups. You can also use chopped Reese's Cups if you can't find the Mini size.