Preheat oven to 350 degrees. Line 8x8 baking pan with parchment paper. Note: you want the parchment paper long enough to hang out of the sides of the pan. Almost like a sling, so you can pull the sides up to remove the bars after baking.
In a microwave safe bowl, combine peanut butter, honey, and oil. Microwave for 30 seconds. Whisk together.
Add vanilla. Whisk again.
In another medium bowl, combine flour, soda, and oats. Mix together with large spoon.
Add peanut butter mixture to medium bowl with oat mixture. Stir until combined. Mix in chocolate chips.
Press granola bar dough into prepared 8x8 baking pan. Press REALLY well - really get in there. This helps keep them from crumbling when you cut them.
Bake for 18-20 minutes. Remove from oven and cool completely in the pan before removing.
Once cool, pull out granola bar square by lifting the parchment paper on opposite sides. Cut into 12 bars or 16 squares. Store in an air tight container on the counter or in the refrigerator for a week. (Longer is safe but they may get stale.)