Preheat oven to 350˚F, adjust the rack to the middle position
With an electric mixer, cream butter & sugars until light, 2-3 minutes, scraping down the sides when necessary.
Add egg and vanilla, mix well.
In a separate bowl, mix together flour, baking powder, baking soda, salt, oats and crispies. Add to creamed butter mixture, mix until incorporated.
Add chocolate chips and nuts (optional), mix.
Drop by tablespoon onto a cookie sheet, about 12 cookies per sheet (see notes)