Step 1: Prepare the Pan

1. Line an 8×8-inch baking pan with parchment paper, leaving enough overhang on the sides to easily lift the fudge out later.
2. Lightly grease the parchment paper with nonstick spray or butter to prevent sticking.

Step 2: Melt the White Chocolate Base

1. In a medium saucepan, combine the white chocolate chips and sweetened condensed milk.
2. Heat the mixture over low heat, stirring continuously until the chocolate chips are fully melted and the mixture is smooth.

Step 3: Add Vanilla Extract

1. Once the chocolate mixture is smooth and creamy, remove it from the heat.
2. Stir in the vanilla extract, mixing well to evenly distribute the flavor.

Step 4: Fold in the Cookies

1. Gently fold in the crushed chocolate sandwich cookies, reserving a small handful for garnish.
2. Stir until the cookies are evenly distributed throughout the fudge mixture.

Step 5: Pour and Garnish

1. Pour the fudge mixture into the prepared baking pan, spreading it out evenly with a spatula.
2. Sprinkle the reserved cookie crumbs on top and press them gently into the surface of the fudge.

Step 6: Chill and Set

1. Place the pan in the refrigerator and chill for at least 3 hours, or until the fudge is completely set.
2. Once firm, use the parchment paper overhang to lift the fudge out of the pan.

Step 7: Slice and Serve

1. Use a sharp knife to cut the fudge into squares. For cleaner cuts, warm the knife under hot water and wipe it dry between slices.
2. Serve immediately or store for later enjoyment.