Preheat oven to 350 °F. In a large bowl cream together the butter and sugar
Add the egg and vanilla, mix smooth
Mix in flour, oatmeal, baking soda and salt
Stir in the chocolate chips, I also added 1/2 cup chopped pecans because I love them!
Press the dough into a baking pan or sided cookie sheet. I strongly recommend using parchment paper or reusable baking sheets, non-stick pans are fine but you have to be careful later on when cutting the bars.
Press the dough to about ½" to ¾" thickness evenly across the pan, leaving about a 1" gap around the edges for the dough to expand as it bakes.
Bake for 15 minutes, edges should be golden and light brown. Cut into bars or squares while warm