1 cup (2 sticks) butter, room temperature
1 cup dark brown sugar, tightly packed
1/2 cup granulated sugar
2 large eggs
1 cup tahini
2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon salt
1/2 teaspoon cinnamon
3 cups old fashioned rolled oats
Preheat oven to 350 degrees Fahrenheit and prepare cookie sheets by lining them with parchment paper.
Beat butter in the bowl of a stand mixer (or using an electric beater) for about 30 seconds. Add the granulated sugar and brown sugar and beat until light and fluffy. Add the eggs and beat until combined. Add the tahini and mix until combined.
In a separate bowl, whisk together flour, baking soda, salt, and cinnamon. Gradually add the flour mixture to the butter mixture until completely combined. Be sure to scrape the sides and bottom of the bowl so the ingredients are well mixed. Stir in 2 cups of the oats until completely combined.
Place the remaining cup of oats in a small bowl. Roll 2-3 tablespoon-sized balls then flatten slightly them into a disk and coat the exterior with the oats and place onto the cookie sheets about 2 inches apart. Bake for 10-12 minutes until the edges are slightly browned and the centers soft. Allow cookies to cool completely on cookie sheet before serving.