Grease a large bowl with cooking spray. Add popcorn and almonds and stir to combine. Set aside.

Line a large sheet pan with foil and grease with cooking spray.

In a medium heavy bottom saucepan over medium-high heat, bring maple syrup to a boil. Boil until maple syrup reaches 300℉ on a candy thermometer. Immediately pour over popcorn and stir vigorously to coat. Quickly spread popcorn mixture onto prepared pan and let cool completely before breaking into pieces.