In a small sauce pan, cook one stick of butter over medium heat. Stirring constantly and scraping the bottom of the pan with a heatproof rubber spatula, until the butter begins to foam and then starts to brown. This will take about 4 minutes.

Remove the browned butter from the heat and allow it to cool in a separate bowl for about one minute. Cut the remaining 1/2 stick of butter into small pieces before adding to the browned butter. Stir to combine.

In a large bowl, mix the browned butter, granulated sugar, and brown sugar together until combined.

Add the whole egg and two egg yolks and whisk until fully incorporated.

Add the vanilla extract and whisk together.

In a separate large bowl, mix together the all-purpose flour, bread flour, rolled oats, baking soda, baking powder, salt, and cinnamon,

Fold the dry ingredients into the wet ingredients until just combined.

Fold in the chopped chocolate chips and chopped walnuts until evenly distributed throughout the dough.

Chill the dough in the refrigerator for 30 minutes before shaping into 1.5 ounce dough balls. Place the cookies 2 inches apart on the cookie sheet to prevent the edges from touching when the dough expands in the oven.

Bake at 375ºF for 12-14 minutes, until cookies are golden brown.