1. Preheat oven to 350°F (175°C). Line an 8×8″ pan with parchment.
2. Melt butter and chocolate in a heatproof bowl over simmering water (or microwave in 30-sec bursts), stirring until smooth. Cool slightly.
3. Whisk in sugar, then eggs + yolk one at a time, then vanilla and ¼ cup Baileys.
4. Gently fold in flour, cocoa, and salt—just until no streaks remain (overmixing = cakey, not fudgy!).
5. Pour into pan. Drizzle remaining 2 tbsp Baileys over surface; swirl gently with a toothpick.
6. Bake 25–28 min—edges set, center still slightly soft (it firms as it cools).
7. Cool completely in pan (at least 2 hours!) for clean cuts. Lift out, slice, and sprinkle with flaky salt if desired.
   💡 Storage: Keep airtight at room temp 3 days or refrigerate (warms beautifully in 10 sec microwave).

PREP TIME & NUTRITION (per brownie, makes 16):
Prep Time: 15 min | Cook Time: 27 min | Total Time: 2 hr 45 min (incl. cooling) | Servings: 16 | Calories: 190 | Net Carbs: 22g | Fats: 10g | Protein: 3g