Preheat your oven to 350°F (175°C) and line your baking sheets with parchment paper.

In a medium bowl, whisk together the flour, baking powder, and salt.

In a mixing bowl, beat together the eggs, egg yolk, sugar, vegetable oil, and vanilla extract until frothy.

Melt the chocolate chips and butter together in a saucepan over medium heat, then stir in cocoa powder and espresso powder.

Pour the chocolate mixture into the egg mixture and stir until just blended.

Gradually add the dry mixture to the chocolate-egg blend, folding until just combined.

Drop spoonfuls of dough onto the prepared baking sheets, spacing them 2 inches apart, and sprinkle with sea salt.

Bake for 8-10 minutes until shiny and crackly on top.

Top warm cookies with extra chocolate chips if desired.

Let cool for about 5 minutes before transferring to wire racks.