line a 9 x 9 inch baking pan with parchment paper.
Mix dry ingredients in a small bowl.
Mix oil, eggs, honey, peanut butter and vanilla in medium bowl, whisking until smooth.
Add dry ingredients to medium bowl and blend thoroughly.
Add any additional ingredients, such as nuts or fruit and blend thoroughly.
Pour into baking pan and pat down with oiled fingers getting the batter into the corners and evenly spread.
Bake at 375 for 15 minutes or until edges are lightly browned. If desired, 2 additional teaspoons of oats can be sprinkled on top about halfway through baking time.
When completely cool move with parchment paper to cutting board and cut into desired number of bars.
Store tightly sealed in refrigerator. Bars can be frozen.