Preheat oven to 350 degrees F.
In large bowl, combine olive oil, brown sugar, and sugar. Add egg, egg yolk, and vanilla paste. Mix until thoroughly combined and mixture is smooth and thick.
In another bowl, whisk together flour, espresso powder, baking soda, and salt. Add flour mixture to large mixing bowl. Stir to combine. Fold in chopped dark chocolate. Mixture will rather dry and crumbly. If it is difficult to mix with a spatula, use your hands to knead together cookie dough.
Immediately portion out dough using a #24 cookie scoop. Arrange cookie balls on a parchment lined baking sheet, spacing them at least 2-inches apart. Bake for 14-16 minutes until cookies have puffed up. Remove from oven and sprinkle sea salt flakes over warm cookies. Allow cookies to cool in pan for 5 minutes before transferring to wire rack. Cookies will slightly flatten as they cool. Enjoy warm or at room temperature.