Preheat oven to 350 degrees. Start by carefully slicing the rind off the top of the Brie wheel, but do not remove completely. Bake for 15 minutes. When the Brie is done baking, the top can be easily removed to expose the creamy cheese. While the Brie is baking, in a medium saucepan, bring Kahlua and brown sugar to a boil and simmer for 10-15 minutes, until a syrupy consistency is made. Throw the pecans in for 2 minutes at the end to warm them through and completely cover with the sauce. Remove the Brie from the oven (removing top rind) and pour Kahlua sauce over the Brie. Serve warm with crackers.