Preheat oven and cookie sheet to 350 degrees. In medium saucepan, melt butter. Add cocoa and stir until dissolved. Add hot water and stir again. With wire whisk, blend in sugar, flour, salt, extract and evaporated milk. Stir until batter is smooth. Mix in pecans and pour into pie shell. Bake on preheated cookie sheet for 50 minutes or until a knife inserted 1 inch from the edge comes out clean. Serve cooled pie with PET WHIP.