1-Preheat and prepare baking sheet: Baking oatmeal cookies is a fun and rewarding process that starts with preheating your oven to 375°F (190°C) and lining a baking sheet with parchment paper to avoid sticking.

2-Beat butter and sugars: Begin by beating the softened unsalted butter in a stand mixer or with an electric beater for about 30 seconds until it’s smooth. Then, add 1 cup (200 g) light brown sugar and ½ cup (100 g) granulated sugar, beating until the mixture is light and fluffy while scraping the bowl as needed.

3-Add eggs and vanilla: Next, add 2 large eggs one at a time, beating until fully combined, and stir in 1 ½ teaspoons vanilla extract for that extra flavor boost.

4-Prepare dry ingredients: In a separate bowl, whisk together 1 ¾ cup (215 g) all-purpose flour, 2 teaspoons cornstarch, 1 teaspoon baking soda, ¾ teaspoon table salt, and ¾ teaspoon ground cinnamon to ensure even distribution.

5-Mix dry ingredients into wet: Gradually mix this dry blend into the butter mixture until everything is fully incorporated, then stir in 3 cups (285 g) old-fashioned rolled oats and any optional 1 ½ cups add-ins like chocolate chips or nuts.

6-Chill dough: After mixing, cover the dough and chill it in the refrigerator for at least 30 minutes or up to 3 days to enhance texture.

7-Portion and bake: Once chilled, drop the dough by rounded 2 tablespoon-sized balls onto the prepared baking sheet, spacing them about 2 inches apart. Bake for 10-12 minutes until the edges are slightly browned, keeping in mind the centers might still be a bit underbaked for that perfect chewiness.

8-Cool and serve: Let the cookies cool completely on the sheet before serving to maintain their softness.