Preheat oven to 400°
In a bowl mix chopped brown sugar, pecans and dijon mustard.
Remove top of rind of of brie. Scoop out 1 teaspoon of cheese for each cup
Place 1 teaspoon of pecan mixture in bottom of cup, top with scoop of cheese, then top cheese with 1 teaspoon of pecan mixture.
Bake for 6 to 8 minutes until mixture if soft and slightly browned
Remove from oven. Let set for 3 to 5 minutes and serve warm.