To make the popcorn:
Pour the oil over the bottom of a large saucepan that has a lid, and add the popcorn kernels. Move them around in the pan so they are in one layer.
Cover the pot, heat it over medium high heat. Once the kernels begin to pop, keep the pan moving until all of the kernels have popped. About 5 to 7 minutes.
Toss the popcorn with the salt and melted butter, then transfer to a bowl. Make sure to pick out the unpopped kernels. You should have about 4 to 4 and ½ cups of popcorn.
To make the dough:
Preheat your oven to 350 F.
In a large bowl cream together the softened butter, brown sugar, granulated sugar, egg and vanilla until smooth.
In another bowl, whisk the flour and baking soda together.
Stir the combined dry ingredients into the butter sugar mixture.
Fold in the cooled popcorn so that it is evenly distributed through the batter. The popcorn will break up a bit here. Just go with it.
Scoop a large tablespoon size mound onto a parchment-lined baking sheet, leaving about 2 inches space in between cookies. The cookbook suggests baking for about 10 to 12 minutes, until the edges are light brown, but my oven liked about 9 to 10 minutes. At 10 minutes, my first batch of cookies were a little darker than I prefer. Let them sit on the pan for a few minutes to firm up before transferring them to a rack to cool.
