Preheat oven to 350 degrees. Line baking sheets with parchment paper. In a medium bowl, whisk together flour, baking soda and salt. In a large bowl, beat butter and sugar at medium speed, with a mixer, until creamy. Add eggs, one at a time. Beating well after each addition. Beat in vanilla. Gradually beat in flour mixture. Stir in chocolate chips. Fold in popcorn.
Drop by tablespoonfuls onto prepared baking sheets. Flatten cookies slightly with the bottom of a jelly glass. Bake 10-12 minutes or until edges are golden brown. Let cool on pan for 2 minutes. Remove from pan and cool completely on wire rack. Cookies may be stored in an airtight container. Makes 3 dozen.