Preheat oven to 350 degree F. Line two cookie sheets with parchment paper (or use a Silpat).

With an electric mixer, beat together the peanut butter and both sugars. Beat in the egg, vanilla, baking soda and salt. Shape dough into about 12 large circles and put them on the baking sheets, 6 to a sheet. Sprinkle with cinnamon sugar or a little extra granulated sugar. Use a fork, slightly dampened, to make criss-crosses.

Bake one sheet at a time for about 12 minutes. Pull the cookies from the oven and quickly stick a Kiss in the center if using. Otherwise, just let sit on cookie sheet for 3-5 minutes; transfer to a rack to cool.