1-First, line an 8-by-8-inch or 9-by-9-inch baking dish with foil or parchment paper, leaving a 2-inch overhang for easy removal. This step makes cleanup a breeze and ensures your fudge comes out perfectly. Next, place the chocolate sandwich cookies in a zip-top plastic bag and roughly crush them with a rolling pin or meat mallet.

2-Remove 1/2 cup of the crushed cookies and set them aside for topping, then crush the rest until finely ground. Over a double boiler or in a heatproof bowl set over simmering water, combine the sweetened condensed milk, white chocolate chips, butter, and vanilla. Stir until smooth, which takes about 5 minutes, to melt everything evenly.

3-Once melted, fold in the finely crushed cookies to add texture without overmixing. Transfer the mixture to your prepared dish and smooth it out with an offset spatula for an even layer. Top with the reserved coarsely crushed cookies, pressing them lightly into the surface for that extra crunch.

4-Chill in the refrigerator for 2 hours until set, then lift out using the overhang and slice into 16 squares.