01. Grease a 12-inch round pan and line the bottom with parchment paper. Whisk together dry ingredients; set aside. Mix both sugars, melted butter, and salt in a mixer until combined.
02. Beat in egg and vanilla. Mix in dry ingredients until just combined. Mix in chocolate chips. Scoop dough into the pan and press it out into an even layer.
03. Bake for 20- 22 minutes, until golden on the edges but soft in the center. Let the cookie cool completely, then invert it onto a cutting board and flip it again onto a plate so it’s right side up.