Preheat the oven to 350°F (175°C) and line two large baking sheets with parchment paper.
In a medium mixing bowl, whisk together the oat flour, baking soda, and sea salt until thoroughly combined.
In a separate large bowl, whisk the melted butter, brown sugar, and granulated sugar until no lumps remain.
Add the egg and vanilla extract to the sugar mixture and whisk vigorously until the batter is smooth and slightly glossy.
Gradually fold the dry oat flour mixture into the wet ingredients using a spatula until just combined.
Fold in the chocolate chips.
Scoop rounded tablespoons of dough onto the prepared baking sheets, spaced 2 inches apart.
Bake for 9 to 11 minutes or until the edges are lightly golden but the centers still appear slightly soft.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.