Oatmeal Cookies

Beat butter in the bowl of a stand mixer (or using an electric beater) for about 30 seconds.
1 cup (226 g) unsalted butter

Add sugars and beat until light and fluffy (pause to scrape down sides and bottom of bowl, if needed).
1 cup (200 g) light brown sugar,½ cup (100 g) granulated sugar

Add eggs, one at a time, beating until combined.
2 large eggs

Stir in vanilla extract.
1 ½ teaspoon vanilla extract

In a separate bowl, whisk together flour, cornstarch, baking soda, salt, and cinnamon.
1 ¾ cup (215 g) all-purpose flour,2 teaspoons cornstarch,1 teaspoon baking soda,¾ teaspoon table salt,¾ teaspoon ground cinnamon

Gradually add flour mixture to butter mixture until completely combined. Be sure to scrape the sides and bottom of the bowl so ingredients are well-mixed.
3 cups (285 g) old-fashioned rolled oats

Gradually stir in oats until completely combined. If using raisins or chocolate chips, stir them in at this point.
1 ½ cups chocolate chips, chopped nuts, or raisins

Gradually stir in oats until completely combined. If using raisins or chocolate chips, stir them in at this point.
1 ½ cups chocolate chips, chopped nuts, or raisins

Preheat oven to 375F (190C) and prepare cookie sheets by lining with parchment paper.

Drop cookie dough by rounded 2 Tablespoon-sized balls onto parchment paper, spacing at least 2" apart. If desired, roll cookies between your palms to make a smooth ball, which will give you more uniform cookies.

Bake on 375F (190C) for 10-12 minutes (edges should be slightly browned, centers may still be slightly underbaked but shouldn't be raw, they'll bake completely as they cool).

Allow cookies to cool completely on cookie sheet before serving and enjoying.