Melt 1/2 cup butter in small saucepan; stir in contents of brown sugar baggie and let cool.
Blend in 2 eggs and 2 teaspoons vanilla extract. Stir in remaining ingredients from the jar and mix well. Spread into a 13 x 9 inch pan. Bake at 325 degrees F for about 30 minutes. The bars will firm up as they cool. While still slightly warm, cut into bars about 2 x 1/2 inches. Remove from pan and roll in confectioners' sugar if desired.
* Put this into a separate zip-top bag and put on top in the jar.