Preheat oven to 250 degrees F.

Place popcorn in a large mixing bowl with enough room to stir (or use two and have a helper).

In a medium saucepan over medium heat, melt butter.

Stir in brown sugar, maple syrup and salt.

Bring to a boil, and cook, stirring, for five minutes. Remove from heat and stir in the baking soda, and vanilla and maple extracts.

Place on two rectangular baking sheets lined with silpat and bake in preheated oven, stirring every 15 minutes, for 1 hour.

Remove from oven and let cool completely before breaking into pieces.