1. Preheat oven to 350°F (175°C). Place a 10″ oven-safe skillet (cast iron preferred) in oven to preheat 5 mins.
2. In a bowl, whisk melted butter, granulated sugar, and brown sugar until smooth. Add egg, yolk, and vanilla; whisk until glossy (~2 mins).
3. Stir in flour, baking soda, and salt just until combined. Fold in all three chocolates.
4. Carefully remove hot skillet from oven. Add dough; press evenly into bottom (it’ll spread as it bakes).
5. Bake 18–20 mins—edges golden and set, center still soft and slightly underdone (it firms as it cools).
6. Immediately sprinkle with flaky sea salt. Let rest 5 mins.
7. Serve warm straight from the skillet with scoops of vanilla ice cream.

PREP TIME & NUTRITION :
Prep Time: 10 mins, Cook Time: 20 mins, Total Time: 30 mins, Servings: 6–8
Calories: 380, Net Carbs: 42g, Fats: 22g, Protein: 4g
✅ Lower-sugar option: Use sugar-free chocolate chips + monk fruit blend — net carbs drop to ~8g/serving.