Preheat the Oven:Preheat your oven to 350°F (180°C) or 160°C fan.
Prepare the Croissants:Using a serrated knife, carefully slice each croissant lengthwise, like a sandwich, but don’t cut all the way through.
Stuff with Cookie Dough:Fill the inside of each croissant with room temperature cookie dough. Add any extra dough on top for a more indulgent finish.
Add Dark Chocolate (Optional):Tuck a few chunks of dark chocolate inside and press some onto the top for extra richness and meltiness.
Bake:Place the stuffed croissants on a lined baking tray and bake for 12–15 minutes, or until the cookie dough is golden and just set.
Finish and Serve:Drizzle with melted chocolate, sprinkle with sea salt, and dust with icing sugar if desired. Serve warm while gooey!