Our take on Austrian Linzer cookies uses hazelnuts instead of the traditional almonds in the dough. If you can buy hazelnut meal, use 140 grams (1½ cups) instead grinding whole nuts as we do, but make sure to toast the hazelnut meal as directed. Plum jam with a smooth texture worked best for the filling; if yours is very thick and chunky, press it through a fine mesh strainer before measuring and simmering. If you do not have a ½-inch-round cutter for making windows in the cookies, the wide end of a standard piping tip also can be used. And if you have Linzer cookie cutters, use them in place of our dough-cutting method. Dough scraps left over after cutting out the circles can be gathered, rerolled, cut and baked into additional Linzer cookies (you'll need more jam to fill them) or into various shapes for nibbling. Assembled cookies will hold for up to 24 hours, but for the best texture wait to finish them until ready to serve. This prevents the jam from softening the cookies as they sit.