Preheat oven to 375 degrees. Microwave butter on high for 40-45 seconds, or until butter is melted. Add sugars, egg, flour and vanilla and mix well. Add pecans, mix well. Using a small scoop, drop dough 2-inches apart onto cookie sheet. Bake 8-10 minutes; until edges are slightly browned. Cool two minutes and remove to cooling rack; sprinkle with powdered sugar. Makes abut 2 dozen.