Start by popping the popcorn kernels using your preferred method (stovetop, air popper, or microwave). Place the popped popcorn in a large mixing bowl.

In a saucepan, combine the sugar, butter, corn syrup, pumpkin pie spice, vanilla extract, and salt. Cook over medium heat, stirring continuously until the mixture comes to a boil.

Once boiling, let the mixture boil without stirring for about 4-5 minutes, or until it reaches a soft ball stage (around 240°F or 115°C on a candy thermometer).

Remove the saucepan from heat and carefully pour the hot mixture over the popped popcorn. Quickly stir until all the popcorn is evenly coated.

Let the mixture cool slightly until it's safe to handle. Then, using buttered hands, form the popcorn mixture into balls, about the size of a golf ball.

Place the formed popcorn balls on a parchment-lined baking sheet to cool completely. Enjoy your delicious Pumpkin Spice Popcorn Balls!