Preheat oven to 375°. Grease a cookie sheet or line with a Silpat mat or parchment paper.
Cream together the butter and sugar. Add the egg, pumpkin, and vanilla, and stir to combine.
Fold in the dry ingredients just until combined. Add any of the optional items that you wish.
Drop dough by heaping teaspoons 2 inches apart on prepared cookie sheets. Bake for 10 to 12 minutes or until the tops are set and the bottoms are golden. Transfer to wire racks to cool.
Notes
I use salted butter, but unsalted will work just as well. Shortening can also be used instead of butter.