Melt the butter, and allow to cool (so it's not piping hot).
Stir in the sugars until well combined.
Stir in the egg and vanilla extract until just combined. Set aside.
In another bowl, stir together the flour, baking soda, and salt.
Stir the dry ingredients into the wet until a soft dough forms.
Stir in the chocolate chips.
Grease an 8x8 baking pan (or line with parchment paper).
Add the batter and gently press so it fills the pan. Sprinkle on the sea salt.
Bake at 325°F for 25-30 minutes. The edges should be brown while the center may still look a little gooey.
Allow to cool before cutting into squares.
