01 -
Whisk together granulated sugar and cocoa powder in a small 1.5-quart saucepan until smooth with no lumps.
02 -
Gradually whisk in the whole milk. Place saucepan over medium-low heat and warm for 3 to 4 minutes, whisking constantly until milk steams and bubbles appear at the edges, avoiding burning.
03 -
Add semi-sweet chocolate chips and stir continuously until fully melted and integrated into the hot chocolate.
04 -
Remove from heat and gently stir in Baileys Irish Cream liqueur until blended.
05 -
Pour the hot chocolate into a 16-ounce mug. Add optional garnishes as desired and serve immediately.