Cream butter, shortening, sugar and eggs, mix well, beat in lemon zest, juice and extract.
Add flour, baking powder and salt, stir in oatmeal.
Chill dough 2-3 hrs (I keep dough for up to 4-5 days and make a few at a time).
Roll dough in walnut sized pieces, toss generously in powdered sugar; place 1-2" apart on ungreased cookie sheet, flatten slightly with the bottom of a juice jar.
Bake at 350 about 12-15 minute or until browned around the edges. Make sure to let them brown enough so they will be crispy.
Cool and serve.
