Remove all unpopped kernals from popcorn. In a 17x12x12 " baking pan, combine popcorn, pecans and cherries. In a 1 quart saucepan combine brown sugar, butter and corn syrup. Cook and stir over medium heat until butter melts and mixture comes to a boil. Cook over low heat 5 minutes more. Remove from heat. Stir in baking soda and vanilla. Pour mixture over popcorn; gently stir to ccoat popcorn mixture. Bake in 300~ oven for 15 minutes;stir. Bake 5-10 minutes more. Remove popcorn to large bowl, cool