Preheat the oven to 350° F. Grease a cookie sheet, and set aside.

In a bowl, add the flour, oats, baking soda, and salt. Whisk to combine, and set aside.

In a separate bowl, add the butter, brown sugar, and white sugar. Using an electric mixer, cream until smooth. Add the egg, and beat again to combine.

Using a spatula, scrape down the sides of the bowl. Add the egg yolk and vanilla, and beat again until the mixture is light and fluffy.

Add the dry ingredients to the bowl of wet ingredients, and stir just until the ingredients are combined and no streaks remain. NOTE: It is important not to overmix! Otherwise, the cookies may not turn out soft and chewy.

Fold in the chocolate chips, dates, and walnuts.

Using a ¼ measuring cup, portion the dough into balls, rolling them between two palms.

Add the dough to the prepared baking sheet, leaving space between each piece.

Bake 11-12 minutes or just until the edges begin to turn a light golden brown. It’s okay if the center sill looks a little gooey!

Let the cookies cool for a few minutes on the baking sheet before transferring them to a wire rack to cool completely.

Store in an airtight container at room temperature for up to 5-7 days.