For the chocolate nut muffins, preheat the oven to 160° hot air. Melt the chocolate in a water bath.
Put the flour in a bowl with the baking powder, nuts and sugar.
Add the egg and milk and mix. Fold in the Baileys and chocolate. Slowly add the butter.
Finally, fill the Chocolate Nut Muffin batter 3/4 full into ramekins and bake for about 20 minutes.