Preheat your oven to 245 degrees.
Line a large baking sheet with parchment paper or a silicone baking mat. In a sauce pan combine the butter, sugar, syrup, pumpkin pie spice together.
On medium-high heat, bring to a rapid boil and boil for five minutes.
Remove from the heat and stir in vanilla extract.
Pour caramel over popcorn mixture and stir to coat.
Place in oven for an hour, stirring every 15 minutes.
Let the popcorn cool and break it apart.
Store in a air tight container.