In a small skillet, add pecans and toast over medium heat for 3 to 5 minutes, until fragrant. Remove pecans from skillet and set aside.
Add butter or margarine to skillet and melt. Stir in sugar and cinnamon. Cook until syrupy and lightly golden brown in color. Remove from heat and stir in vanilla. Then stir in pecans until well coated.
Spread pecans onto a baking sheet and bake at 300 degrees for 30-40 minutes, until dry and crispy.