Brown Butter Oatmeal Chocolate Chip Bars

0 Preheat your oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving some overhang for easy removal.
1 In a saucepan over medium heat, melt the butter, stirring continuously until it turns golden brown and smells nutty. Remove from heat and let cool slightly.
2 In a large bowl, whisk together the brown butter, brown sugar, and granulated sugar until smooth. Add the egg, egg yolk, and vanilla extract, and mix until fully combined.
3 In a separate bowl, whisk together the flour, oats, baking soda, and salt.
4 Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Fold in the chocolate chips.
5 Transfer the dough into the prepared baking pan, spreading it evenly. Sprinkle with flaky sea salt if desired. Bake for 25-30 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out with a few moist crumbs.
6 Let the bars cool in the pan for at least 20 minutes before slicing. Enjoy warm or at room temperature!