Begin by air-popping your popcorn. You can use an air popper or a stovetop method. Once popped, place the popcorn in a large mixing bowl. Make sure to remove any unpopped kernels to avoid any surprises later on.
In a medium saucepan, combine the honey, granulated sugar, and natural peanut butter. Place the saucepan over medium heat and stir continuously until the mixture is smooth and well combined. This usually takes about 3-5 minutes. Remove from heat and stir in the vanilla extract until fully incorporated.
Pour the warm peanut butter mixture over the popcorn in the large bowl. Using a spatula, gently fold the popcorn to coat it evenly with the mixture. Take your time to ensure every piece is covered in that delicious peanut butter goodness.
Melt the milk chocolate chips in a microwave-safe bowl in 30-second intervals, stirring between each until smooth. Drizzle the melted chocolate over the coated popcorn, using a spatula to mix it in gently.
Once your popcorn is coated in the peanut butter and chocolate mixture, add the Mini Reese's Peanut Butter Cups. Gently fold them in, being careful not to break them apart too much.
Spread the popcorn mixture onto a lined baking sheet in an even layer. Allow it to cool completely at room temperature. This helps the chocolate and peanut butter set, ensuring that your popcorn will hold together beautifully.
