Preheat oven to 350 degrees. Line a 9x13 baking pan with foil and spray with nonstick cooking spray.

In a large bowl, combine dry ingredients: oats, flour, baking soda and salt.

In another bowl, beat sugar and butter until creamy. Beat in yogurt, eggs and vanilla until smooth.

Add flour mixture to wet ingredients, gently stirring until a dough forms. Fold in chocolate chips.

Press dough evenly into prepared pan. Bake for 25-30 minutes or until bars begin to turn golden around the edges.

Cool completely in pan, then lift out with foil. Slice into squares.