Place the butter in a medium saucepan and melt over medium heat, stirring often, until it foams, smells nutty, and browns. This will take about 5 to 7 minutes. Scrape the browned butter into a small bowl. Cover and place in the fridge so it can cool while you prep the other ingredients.

In a medium bowl, whisk together the flour, baking soda, salt, and cinnamon. Set aside.

In the bowl of a stand mixer or with a hand mixer, beat the brown butter and sugars together until smooth, scraping down the sides of the bowl with a spatula as necessary.

Add the eggs and vanilla extract. Mix until combined.

Add the dry ingredients and mix on low until just combined. Don’t over mix. Stir in the oats, chocolate chunks, pecans, and dates.

Scoop the cookie dough into balls, about 2 tablespoons of dough per cookie. Place onto a plate or baking sheet that has been lined with parchment paper. Cover the balls with plastic wrap and refrigerate for a minimum of 30 minutes. The dough can be chilled for up to 48 hours.

When ready to bake, preheat the oven to 350 degrees F. Remove the dough balls from the fridge to allow them to soften a little while the oven preheats. Place the balls on a large baking sheet with parchment paper, about 2-inches apart.

Bake for 10 to 12 minutes or until cookies are golden brown around the edges but still soft in the center.

Remove from the oven and sprinkle with a little flaky sea salt. Let the cookies cool on the baking sheet for 5 minutes. Transfer to a cooling rack to cool completely.