Add 1 tablespoon of vegetable oil to a 4-quart saucepan and heat over high heat.

Once the oil is hot, add 1/2 cup of popping corn and keep the pan moving constantly to prevent burning.

When the popping slows down, remove the pan from heat and place the popped corn in the oven to keep it warm.

In a medium saucepan, combine the butter, brown sugar, and corn syrup.

Stir well and bring to a boil over medium heat.

Stir in the sweetened condensed milk and continue simmering, stirring constantly, until the mixture thickens.

Remove from heat and stir in the vanilla extract.

Pour the hot caramel over the warm popped corn, stirring well to coat all pieces evenly.

Lightly butter your hands and shape the coated popcorn into balls, pressing gently to form each one.