1Heat oven to 200°F. Divide popcorn between 2 ungreased 13x9-inch pans.
2In 3-quart heavy saucepan, heat brown sugar, butter, corn syrup and salt over medium heat, stirring occasionally, until bubbly around edges. Cook 5 minutes longer, stirring occasionally; remove from heat. Stir in baking soda.
3Pour caramel mixture over popcorn; stir until well coated. Add 1 cup cranberries and 3/4 cup baking chips to each pan; toss until well coated. Bake 1 hour, stirring every 15 minutes. Spread on waxed paper or foil to cool. Store in airtight container.