Pecan Penuche

In 3 quart saucepan over medium heat, heat sugars and milk to boiling, stirring constantly. Set candy thermometer in place and continue cooking without stirring, until temperature reaches 238 deg F. or until a small amount of mixture dropped into very cold water forms a soft ball. Remove from heat. Add butter and vanilla. Cook mixture, without stirring, to 110 deg F. or until outside of saucepan feels lukewarm to hand. Meanwhile, butter 8 x 8 inch pan. With spoon, beat until mixture becomes thick and begins to lose its gloss. Quickly stir in pecans. Pour into pan. (do not scrape saucepan. Mixture on side may be sugary.) Cook in pan on wire rack. When cold, cut into squares with a sharp knife.