Preheat the oven to 350 degrees F. Line cookie sheet with parchment paper, or spray with nonstick spray.: Warmth fills the kitchen as the oven comes up to temperature, and that dry, toasty scent primes the space for baking. Preheating ensures cookies bake evenly so they set properly and do not spread too much, which matters for texture. Lining the cookie sheet prevents sticking and promotes golden bottoms, while parchment helps lift cookies cleanly. A common mistake is not allowing the oven to fully preheat, which can lead to uneven baking and underdone centers. If your oven runs hot, use an oven thermometer to confirm the temperature.
In a large bowl, use an electric mixer to cream together the shortening and sugars. Add the eggs and vanilla and beat well. Set aside.: The inevitable light, airy mixture you see when creaming is vital, it traps tiny pockets of air that help the cookies rise slightly and give a tender crumb. You should notice the texture going from grainy to smoother, and the color lightening a touch. When you add the beaten eggs and vanilla extract , the batter becomes glossy and cohesive. If you undercream, the cookies can be dense, and overbeating after adding eggs can cause excess liquid, changing spread. Use medium speed and scrape the bowl so everything blends uniformly.
Sift together the flour, salt, baking soda and cinnamon. Add the dry ingredients to the wet and mix well. Add the nuts and/or raisins, if desired. Stir in the oats last.: The sifted dry mix should smell faintly spicy from the ground cinnamon and look uniformly pale. Folding the dry into the wet gradually prevents streaks of flour and helps maintain a tender texture. Adding mix ins before the oats helps them distribute, and stirring in the old fashioned oats last preserves their shape and chew. If you mix the oats too early or overwork the dough, they can break down, resulting in a gummy cookie. Watch for a dough that looks cohesive but not greasy, and that the oats are evenly scattered.
Spoon out by rounded teaspoonfuls onto greased cookie sheets. Bake for 10 minutes. Remove to a wire rack and cool completely.: As you portion the dough, you will notice a slightly sticky, malleable consistency that holds shape but will spread a bit while baking. Aim for evenly sized mounds to ensure even bake time. While baking, listen for faint bubbling and watch the edges for a gentle deepening of color, which signals readiness. The centers will still look soft when you pull them, they firm as they cool on the wire rack. A common error is overbaking, which yields hard, dry cookies, so err on the side of a slightly underbaked center for a tender chew. Cooling on wire racks prevents steam from soggy bottoms and lets the cookies set properly.
