Heat oven to 375.
In a large mixing bowl, beat butter until smooth.
Add sugars, baking powder, baking soda and cinnamon, beating until combined.
Beat in eggs and vanilla.
Beat in flour
Beat or stir in rolled oats.
Beat or stir in chocolate chips.
Drop dough with a giant spoon onto parchment lined baking sheets. The portion should be somewhere between the size of a golf ball and a tennis ball. Flatten the ball out a bit with the back of the spoon.
Bake for 12-14 minutes until the edges are a lovely golden colour.
Cool on a wire rack and store in an airtight container.