Preheat oven to 180 degree C. Line a 10 cm square pan with parchment paper and set aside.
Take chocolate and butter in a microwave safe bowl and melt in microwave for 1 min.
Remove and mix well.
Add sugar, egg and mix well.
Add in baileys and mix well.
Add in flour and fold gently.
Spoon this into the baking pan and bake for 25 to 30 mins.
Remove and cool completely.
Slice and serve.