*The walnuts are tastier if you toast them before chopping. Place walnut pieces in a single layer in a flat pan and toast them in a preheated 350°F oven for 7 to 9 minutes, or until they smell "toasty" and are beginning to brown.
In a large bowl, combine the flour, walnuts, baking powder and salt. Cut in the shortening and/or butter until the mixture resembles coarse crumbs.
In a separate bowl, combine the milk, 1/3 cup (3 3/4 ounces) of the maple syrup, and the maple flavoring. (You can leave out the maple flavoring if you wish, but it really adds a nice touch.) Add the wet ingredients to the dry ingredients and mix until you've formed a very soft dough.
Flour your work surface generously, and scrape the dough out of the mixing bowl onto the floured surface. Divide the dough in half.
Working with one half at a time, gently pat the dough into a 7-inch circle about 7/8-inch thick. Transfer the circle to a parchment-lined or lightly greased cookie sheet or other flat pan; it'll be very soft, and if you have a giant spatula, it's the tool of choice here. Repeat with the remaining half of the dough, placing it on a separate pan.
Using a sharp bench knife or rolling pizza wheel, divide each dough circle into eight wedges. Gently separate the wedges so that they're almost touching in the center, but are spaced about an inch apart at the edges. Pierce the tops of the scones with the tines of a fork, and brush them with some of the remaining maple syrup.
Bake the scones in a preheated 425°F oven for 15 to 18 minutes, or until they're golden brown. Remove them from the oven, and brush them with any remaining maple syrup. Wait a couple of minutes, then gently separate the scones with a knife (they'll be very fragile), and carefully transfer them to a cooling rack. Serve warm or at room temperature, with jam or maple butter (or even better, maple cream, an amber-colored, spreadable version of maple syrup, available at just about any New England shop selling native maple syrup).