Preheat oven to 350 degrees.

Grease or line an 8×8-inch baking pan with parchment paper to prevent sticking.

In a large mixing bowl, whisk together melted butter and white sugar until smooth.

Add eggs one at a time, mixing well after each addition.

Stir in Baileys Irish Cream until completely incorporated.

In a separate bowl, sift together flour, unsweetened cocoa powder, and salt. Gradually fold dry ingredients into the wet mixture, mixing until just combined. Avoid overmixing to ensure tender brownies.

Transfer batter to prepared pan and spread evenly.

Bake for 20–25 minutes (don't over bake), or until a toothpick inserted in the center comes out with moist crumbs. Allow brownies to cool completely in the pan.

FROSTING: In a medium bowl, beat softened butter until creamy. Gradually add powdered sugar, mixing thoroughly. Pour in Baileys Irish Cream and continue beating until frosting is smooth. If needed, add heavy cream or milk in small increments until a spreadable consistency is achieved.

Spread frosting evenly over cooled brownies. Top with mini chocolate chips, if desired. For extra visual appeal, create a decorative drizzle by piping melted chocolate chips in a zig-zag pattern.

Allow frosting to set before slicing and serving for clean cuts.