Preheat & prep: Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.
Mix dry ingredients: In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
Combine wet ingredients: In a large bowl, whisk together melted butter, brown sugar, and granulated sugar until smooth and glossy. Add the egg, egg yolk, and vanilla, and mix until combined.
Bring it together: Slowly add the dry ingredients to the wet ingredients, stirring with a spatula or wooden spoon until a dough forms—don’t overmix!
Add chocolate: Fold in chocolate chips (and chopped chocolate if using). The dough will be soft but scoopable.
Scoop & shape: Use a cookie scoop or 2 tbsp of dough per cookie. Roll lightly and space 2 inches apart on baking sheets.
Bake: Bake for 10–12 minutes, until edges are golden but centers are still soft and puffy.
Cool: Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack. Sprinkle with flaky salt if desired.
