30–45 minutes before baking, remove the butter and eggs from the refrigerator. The butter should be soft enough to leave a gentle dent when pressed but not greasy or shiny. Room-temperature ingredients cream and combine more evenly, helping the cookies bake up thick and tender.

Preheat the oven to 350°F (175°C). Line two large baking sheets with parchment paper or silicone baking mats to prevent sticking and over-browning.

In a large mixing bowl or the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter, brown sugar, and granulated sugar together on medium speed for 3–4 minutes, until lighter in color and slightly fluffy. This step helps create crisp edges and chewy centers.

Add the eggs one at a time, beating well after each addition and scraping down the bowl as needed. Mix in the vanilla extract until smooth. The mixture may look slightly separated; it will come together once the dry ingredients are added.

In a separate bowl, whisk together the flour, baking soda, baking powder, fine sea salt, and ground cinnamon (if using) until well combined and no clumps remain.

Add the dry ingredients to the butter mixture in two additions, mixing on low speed just until the flour is mostly incorporated. Do not over-mix, as this can make the cookies tough.

Using a sturdy spatula or wooden spoon, stir in the rolled oats, chocolate chips or chunks, chopped pecans, and shredded coconut by hand. The dough will be thick and chunky.

Cover the bowl and chill the dough in the refrigerator for at least 45–60 minutes, or up to 48 hours. Chilling allows the flour and oats to hydrate, the flavors to develop, and helps the cookies bake up thicker with less spread.

Using a medium to large cookie scoop, portion 2–3 tablespoons of dough per cookie for classic 3–3.5-inch cookies. Roll each portion into a ball and place on the prepared baking sheets, leaving about 3 inches between cookies. For jumbo bakery-style cookies, use about 1/4 cup dough per cookie and space them further apart.

Bake one sheet at a time on the center rack for 11–14 minutes, depending on cookie size. The edges should look set and lightly golden, while the centers remain slightly soft and puffy. For smaller 1-tablespoon cookies, start checking around 8–10 minutes. The cookies will continue to set as they cool.

Immediately after removing the cookies from the oven, sprinkle each warm cookie with a small pinch of flaky sea salt, if using, to enhance the chocolate flavor and balance the sweetness.

Allow the cookies to cool on the baking sheet for 5–10 minutes, then transfer to a wire rack to cool completely. Enjoy warm for gooey centers or at room temperature for a chewier texture.

Store completely cooled cookies in an airtight container at room temperature for 4–5 days. To freeze baked cookies, freeze on a baking sheet until firm, then transfer to an airtight container or freezer bag for up to 2–3 months. For unbaked dough, scoop into balls, freeze until solid, then store frozen. Bake frozen dough balls at 350°F, adding 1–2 minutes to the bake time.