01 - Line an 8-inch square baking pan with parchment paper, leaving an overhang on opposite sides for easy removal of the fudge later.
02 - Combine white chocolate chips, sweetened condensed milk, and butter in a medium saucepan over low heat. Stir continuously until completely melted and smooth, ensuring the chocolate doesn't scorch.
03 - Remove from heat and stir in heavy cream, Irish cream coffee creamer, vanilla extract, espresso powder if using, powdered sugar, and salt. Mix until the mixture is fully incorporated and silky smooth.
04 - Pour the fudge mixture into the prepared pan. Use a spatula to spread evenly and smooth the top surface.
05 - Refrigerate for a minimum of 2 hours until completely firm and set throughout.
06 - Lift the fudge from the pan using the parchment paper overhang. Cut into 36 equal squares. Store in an airtight container in the refrigerator for up to 2 weeks.