In a small bowl, combine crushed gingersnaps and melted butter until evenly coated. Divide among serving cups (about 6–8 small cups or jars) and press lightly to form a base.
In a large bowl, beat cream cheese, pumpkin, brown sugar, vanilla, pumpkin pie spice, and cinnamon until smooth and creamy.
In a separate bowl, whip heavy cream and powdered sugar until soft peaks form.
Gently fold whipped cream into pumpkin mixture until fully combined and fluffy.
Spoon or pipe mousse over the cookie base. Chill for at least 2 hours or up to 24 hours before serving.
Just before serving, top with whipped cream and a sprinkle of crushed cookies or a gingersnap half.