01 - Line an 8x8-inch baking pan with parchment paper, leaving overhang on opposite sides for easy removal of the squares.
02 - Combine chocolate cookie crumbs and melted butter in a medium bowl. Mix until evenly moistened. Press firmly into the bottom of the prepared pan to create an even layer. Set aside.
03 - Place white chocolate chips in a heatproof bowl set over a pan of simmering water, creating a double boiler. Stir continuously until completely smooth and melted. Remove from heat.
04 - Beat the softened cream cheese in a large bowl until completely smooth and creamy, with no lumps remaining.
05 - Pour the melted white chocolate over the cream cheese. Add sweetened condensed milk, Irish cream liqueur, peppermint extract, and salt. Beat on medium speed until thoroughly combined and silky smooth. Add green food coloring a few drops at a time until desired color is achieved.
06 - Pour the cheesecake fudge mixture over the prepared crust. Use a spatula to spread evenly and smooth the top surface.
07 - Refrigerate for at least 3 hours, or until completely firm and set throughout.
08 - Once fully set, drizzle melted dark chocolate over the top. Sprinkle with green decorations while chocolate is still wet.
09 - Use the parchment paper overhang to lift the fudge block from the pan. Cut into 16 equal squares using a sharp knife, wiping the blade clean between cuts for neat edges.