Preheat your oven to 375°F (190°C) and line a large baking sheet with parchment paper.

In a medium bowl, whisk together 1.25 cups flour, 0.5 teaspoons baking powder, 0.25 teaspoons baking soda, and 0.5 teaspoons salt.

In a large mixing bowl, cream together 6 tablespoons unsalted butter, 0.5 cups light brown sugar, and 2 tablespoons granulated sugar until smooth and fluffy.

Add in 1 large egg and 1 teaspoon pure vanilla extract, and beat until combined and the batter is smooth.

Gradually fold in the dry ingredients from Step 2 until just incorporated.

Fold in 1 cup semisweet chocolate chips and 0.33 cups chopped walnuts if using, until evenly distributed.

Using a 2-ounce cookie scoop, portion the dough, keeping it rough and rustic. Space about 3 inches apart on the baking sheet.

Bake the cookies at 375°F (190°C) for 10 minutes, then reduce the temperature to 350°F (175°C) and bake for an additional 5-7 minutes until edges are golden brown.

Remove from the oven and let cool on the baking sheets for about 3 minutes before transferring to a wire rack.