Preheat your oven to 350°F (175°C).
Grease and line a 9x13 inch baking pan with parchment paper.
In a saucepan, melt the butter over low heat.
Remove the saucepan from the heat and stir in the sugar.
Add eggs one at a time, mixing well after each addition.
Stir in the vanilla extract and Baileys Irish Cream.
Sift together flour, cocoa powder, baking powder, and salt in a separate bowl.
Gradually fold the dry ingredients into the wet mixture.
Stir in the chocolate chips, ensuring even distribution.
Pour the batter into the prepared baking pan and smooth the top.
Bake in the preheated oven for 25-30 minutes, or until set.
Allow the brownies to cool in the pan for about 10 minutes before lifting them out.