Combine corn syrup, sugar, brown sugar, and peanut butter in a large saucepan. Bring to a boil over low heat, stirring constantly; boil 2 to 3 minutes. Remove saucepan from heat. Combine popcorn and raisins in large bowl; pour hot mixture over popcorn and toss carefully with wooden spoons to mix until well-coated. Spray 9- x 13-inch baking dish with cooking spray; press popcorn mixture into pan and cool completely. Cut into squares and serve. Makes 12 squares.