1. Preheat oven to 325°F. Prepare two baking sheets with parchment paper.
2. Beat together the butter and sugars until light and fluffy, about 3 minutes. Add in the egg, vanilla, beat for 1 minute.
3. In a separate bowl blend together the oat flour, oats, baking powder, baking soda, cinnamon and salt. Gradually add flour mixture to wet ingredients and mix thoroughly with a wooden spoon until dough forms. Stir in butterscotch chips.
4. To achieve evenly sized cookies try using a cookie scoop, or a rounded tablespoon, placing 12 spoonfuls onto a cookie sheet, evenly spaced apart. Bake in preheated oven for 15 minutes or until golden in colour. Remove from oven; wait a couple minutes then transfer to cool on wire rack. Repeat with remaining cookie dough.
5. Best eaten same day or stored in an airtight container for up to 5 days, if you can resist them that long!

TIP: This recipe can easily be converted into a vegan cookie. Substitute the butter for vegan margarine and substitute the butterscotch chips for vegan chocolate chips or raisins, also replace the eggs with 1 tablespoons of ground flaxseed mixed with 3 tablespoons of warm water and left to thicken for 5 minutes.