Preheat the oven to 350F and line a large baking sheet with parchment paper.
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
In a large mixing bowl, whisk together the butter, sugar, and maple syrup, followed by the milk, egg yolk, and vanilla.
Pour in the dry ingredients and use a rubber spatula to fold the dough together.
Add the chopped chocolate and fold to combine.
Using a large 3-tablespoon cookie scoop, scoop the cookie dough out onto the baking sheet and space them well apart.
Bake for 12-15 minutes or until the edges are golden brown and the center looks a bit lighter than the outside.
Sprinkle with flaky sea salt and transfer to a cooling rack to cool completely.
