Start by preheating your oven to 350°F (175°C). Prepare two baking sheets by lining them with parchment paper or silicone mats to prevent sticking.

Using a large mixing bowl, beat together the softened butter, brown sugar, and sugar until the mixture becomes light and fluffy, about 2 to 3 minutes.

Add the eggs one at a time, ensuring each is fully mixed in before adding the next. Stir in the vanilla extract to combine.

In a medium bowl, whisk together the flour, baking soda, ground cinnamon, and salt. Gradually add this dry mixture into the wet ingredients, folding it in until just combined.

Gently mix in the rolled oats until they are evenly distributed. The dough will feel thick and slightly sticky.

Cover the bowl with plastic wrap and refrigerate the dough for at least 30 minutes. Chilling is essential for creating thick cookies that don’t spread too much when baked.

Once chilled, use a cookie scoop or spoon to portion out dough balls roughly the size of 2 tablespoons. Place them on the prepared baking sheets, leaving about 2 inches of space between each one.

Bake the cookies for 10 to 12 minutes, or until the edges turn golden and the centers look just set. Avoid overbaking for a softer texture.

Allow the cookies to rest on the baking sheets for about 5 minutes before transferring them to a wire rack. Cool completely before serving, and enjoy!