Preheat oven to 425 degrees. Combine the flour, cornmeal, sugar, baking powder, baking soda, salt and cinnamon. Cut the butter into the flour mixture with a food processor or pastry cutter until it resembles small peas. Mix in the nuts and/or fruit. Mix in the buttermilk and turn onto a board sprinkled with about 1/2 cup cornmeal. Knead lightly, then roll out to about 1/2-inch thick. Try to keep the dough in as much of a square shape as possible - this will facilitate cutting it. With a knife or pizza cutter, cut the dough into triangles, squares or rectangles; cookie cutters may also be used. Place the scones on an ungreased cookie sheet and bake for 12 minutes, rotating the pan halfway through the cooking time to insure even baking. Serve with jam.