Preheat oven to 200°F (95°C).Place popped corn in a large, ungreased roastingpan or divide popped corn between two 13 x 9 x 2-inch bakingpans (less desirable but it works, see note).
Combine sugar, butter, corn syrup andsalt in 2-quart or larger saucepan. Bring to a boilover medium heat, stirring occasionally. Cook for 5 minutes,without stirring. Remove from heat,stir in flavoring, food coloring (if using) and the baking sodaand mix well. Mixture will become foamy.
Immediately pour hot mixture over poppedcorn and quickly toss to coat. (Ordivide evenly between the two pans.) Don’t expect all corn tobe coated, that will happen in the course of baking.
Bake for 1 hour, stirring every 15 minutes.Remove from oven, immediately turn out of pan(s) onto a foil-linedcounter top and break up slightly. Cool. Storein tightly sealed container.