In a large bowl, combine 15 cups popped popcorn, 2 cups miniature marshmallows, 1 cup salted peanuts and 1 cup broken pretzel sticks. In a small saucepan, combine ⅔ cups sugar, ½ cup butter and ¼ cup corn syrup. Bring to a boil; cook and stir 2 minutes. Pour over popcorn mixture; toss to coat. Cool on waxed paper then break it up.
In a large saucepan, melt 1½ cups butter. Add 2⅔ cups brown sugar and 1 cup golden syrup, stirring to dissolve brown sugar. Bring to a full rolling boil. Boil and stir 1 minute. Remove from heat and quickly stir in 1 teaspoon vanilla. Pour caramel mixture over 24 cups popped popcorn, stirring lightly. Cool on waxed paper then break it up.