Brown the Butter: In a medium saucepan, melt unsalted butter over medium heat, stirring frequently, until it turns golden brown. Remove from heat and transfer to a bowl to cool for approximately 15 minutes.

Preheat Oven: Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

Mix Dry Ingredients: In a large mixing bowl, whisk together all-purpose flour, bread flour, baking soda, salt, and rolled oats until fully combined.

Combine Wet Ingredients: Beat the cooled brown butter and brown sugar together until smooth. Add the egg, egg yolk, maple syrup, vanilla extract, and optional maple extract, mixing until blended.

Incorporate Dry Mixture: Gradually add the dry mixture to the wet ingredients, mixing on low speed until just combined. Fold in the chopped toasted pecans.

Shape Cookies: Portion out the dough onto the prepared baking sheets, spacing them about 2 inches apart. Flatten each scoop slightly.

Bake: Bake for 12-14 minutes, or until the edges are lightly golden and centers appear set.

Cool: Let the cookies cool on the baking sheets for about 5 minutes before transferring to wire racks to cool completely.