Preheat your oven to 350 degrees. Line your pan with a silicone baking mat or parchment paper for easy clean-up.
In a large bowl, cream together the butter and sugar.
Whisk in the eggs, one at a time until fully combined.
Add the vanilla extract, baking soda, and 1 1/4 tsp salt.
Slowly mix in the flour.
Fold in the dark and semi-sweet chocolate chips.
Scoop 1-inch balls of cookie dough onto your cookie sheet.
Bake for 7-8 minutes, until golden brown just at the edges.
Remove cookie sheet and sprinkle top of cookies with a little bit of coarse sea salt.
Let cool on the cookie sheet for 10 minutes and then transfer to a cooling rack to cool completely.
Repeat with remaining cookie dough until it is all used up.