In a microwave, cook or pecans, sugar, corn syrup for 4 minutes. Add a teaspoon of butter or margarine and a teaspoon of vanilla, stir and cook for 2 minutes more.
Remove and add a teaspoon of baking soda. Stir until light and foamy.
Pour into a greased cookie sheet, let cool one hour. Flip over and crack with back of a spoon into desired pieces.
Note: Be sure to use a microwave safe bowl. Be very careful not to get the hot mixture on you. You may have to adjust times according to your microwave.