Line an 8x8-inch (or larger) baking pan with parchment paper. Leave some paper hanging on two sides, it will help to remove the three-ingredient Oreo fudge from the pan. Set aside.
Add 20 Oreo cookies to a ziplock bag. Then, crush the Oreo cookies a little using a rolling pin. Set aside.
Add sweetened condensed milk and white chocolate chips to a saucepan. Heat over low heat until melted and completely combined, stirring constantly. Then, turn off the heat.
Remove a saucepan from the stove and stir in crushed Oreo cookies. Then, transfer this mixture to the prepared baking pan. Decorate your Three-ingredient Oreo fudge with the remaining 4 Oreo cookies, break them and sprinkle on the top of the fudge.
Cover with a plastic wrap and place in the refrigerator until 3 ingredient Oreo dessert sets. Usually, it takes about 1-2 hours. When ready to serve, remove from the refrigerator and out of the baking pan, cut into squares and enjoy!