Swirl Squares

1/2 cup butter
1/2 cup packed brown sugar
1/4 cup sugar
1/2 tsp. vanilla
1 egg
1-1/8 cups flour
1/2 tsp. baking soda
1/2 tsp. salt
1/4 cup chopped pecans (optional)
1 cup milk chocolate chips

Beat butter with sugars.  Add egg and vanilla.  Mix in dry ingredients and nuts.  Spread in 9x9" pan (or small rectangle pan) lined with foil and sprayed (or lined with parchment paper).  Sprinkle chocolate chips evenly over top.  Bake in 375 degree oven for 2-3 minutes until chips are soft enough to marble.  Run knife through batter to obtain a marble effect.  Continue to bake for about 15-20 minutes more, until firm and done (They will look quite browned).  Cool and lift out of pan to cut.