Melt two tablespoons of butter in a frying pan over low heat, add pecans and toss to coat. Add brown sugar and stir, watching closely, until they are melted and caramelized (about two minutes). Remove from heat and continue browning in pan for another minute. Remove from pan and cool pecans on parchment paper. While they are still sticky and not yet cool, sprinkle with a little coarse black pepper.