Sift whole wheat flour a second time with the cream of tarter, baking soda salt and cinnamon. Set aside. In a medium-size bowl, cream the butter until fluffy, scraping down the sides of the bowl. With the mixer still running, add the maple syrup in a thin stream, followed by the eggs, one at a time. Gradually stir the dry ingredients into the creamed mixture, stirring just until blended. Cover and refrigerate for 30 minutes. Preheat the oven to 200ºC F.and put the sugar in a small bowl. With lightly floured hands,roll the dough into balls about 3 cm in diameter. Roll the balls in the sugar,then place on an ungreased baking sheet, leaving 5 cm between them. Bake for 10 minutes, just until tops no longer yield to light finger pressure. Transfer to a rack and cool. Store in an airtight container