Preheat oven to 350°F; line two baking sheets with parchment. Whisk flour, baking soda, and salt in a bowl.
Whisk olive oil and both sugars well in a large bowl; whisk in eggs and vanilla until smooth and emulsified.
Stir flour mixture into wet ingredients just until combined; fold in chocolate chips and toasted walnuts.
Scoop rounded tablespoons onto prepared sheets; sprinkle with flaky salt. Bake 10-12 minutes, until edges set and centers remain soft.
Cool on sheet 3 minutes; transfer to wire rack to finish cooling.