Combine flour, baking soda, salt, and cinnamon in a small bowl. Beat butter, granulated sugar, brown sugar, eggs, and vanilla extract in a large mixer bowl.
Gradually beat in flour mixture. Stir in oats and morsels. Drop by rounded tablespoon (or with a cookie scoop) onto ungreased baking sheets.
Bake for 6 to 7 minutes for chewy cookies or 8 to 9 minutes for crispier cookies. Cool on a baking rack for at least 5 minutes; remove to wire racks to cool completely.
Notes
FLOUR: Make sure to spoon the flour into the measuring cup and level it off with a knife for an accurate measurement.
These cookies tend to spread a little while in the oven, so make sure your baking soda is fresh.
For the best texture, use old-fashioned rolled oats. However, quick-cooking oats are okay to use.
The secret to chewy cookies with a slight crisp on the edges is this baking mat. No joke!
Let the cookies cool on the baking sheet for at least 5 minutes before moving them to the cooling rack. They come out of the oven very soft.
Let the baking sheet cool completely before adding the next batch.
You can store your homemade cookies at room temperature for two to three weeks or two months in the refrigerator.Make-Ahead Instructions: You can make the cookie dough and chill it in the refrigerator for up to 4 days. Allow to come to room temperature, then continue with baking. Unbaked cookie dough balls freeze well for up to 3 months. Bake frozen cookie dough balls for an extra minute. No need to thaw.Nutritional information is approximate and was calculated using a recipe nutrition label generator and will vary based on cooking methods and brands of ingredients used.