Combine flour & pecans in food processor and process until fine.
Beat butter and sugars until light and fluffy.
Stir in flour mixture.
Mix in cinnamon.
Wrap dough in plastic wrap and refrigerate overnight.
On lightly floured surface, roll dough to 1/4" thickness. Cut out dough with a thimble. Place on foil-lined cookie sheet and bake at 300 degrees until lightly browned (about 9 minutes).
Instead of dusting the rolling surface with flour, I use powdered sugar. Also, I occasionally dip my thimble in the powdered sugar to prevent sticking. If your dough gets lodged in the thimble, use a toothpick to carefully remove it. I went through about five cookie sheets; once one was filled, I popped it in the oven and continued to cut cookies. Continue to re-roll your dough until it becomes too small to cut.