In large bowl, beat butter and sugars with electric mixer until creamy. Add egg and vanilla; beat well.
In a separate small bowl, combine flour, bread soda and salt. Mix these into the butter mixture.
Stir in oats and chocolate chips; mix well.
Press dough evenly into bottom of an ungreased10-inch non-stick ovenproof skillet. Bake 20 minutes or until top is lightly browned. Do not overbake as cookie will continue to bake after it is removed from oven. Cool about 10 minutes. Cut into 8 wedges. Serve with vanilla ice cream.