Make Classic Shortbread dough, beating 1 1/2 teaspoons ground cinnamon and 1/2 teaspoon ground cardamom with the butter. Pat into a 1/4-inch-thick square on parchment paper, then cut into 1-inch squares and chill 30 minutes. Sprinkle with cinnamon-sugar and bake 12 to 15 minutes at 375 degrees.