Mix together the sugar, corn syrup, butter, cocoa powder, and salt in a saucepan over medium-low heat until the mixture is smooth and begins to simmer. Place the popcorn into a very large bowl, mix with the almonds, and then pour the chocolate syrup over the mixture. Stir until all the popcorn and almonds are coated. Spread the chocolate popcorn out onto several large baking sheets in a single layer.
Bake in the preheated oven until thoroughly dry, about 1 hour, stirring every 20 minutes or so to dry all sides of the popped corn. Allow to cool on the sheet, then transfer into sealed containers.
