Line an 8x8 or 9x9-inch baking dish with parchment paper, leaving some overhang for easy removal.
Roughly chop the Oreos and vanilla almond bark. (Alternatively, break the Oreos into larger pieces for a chunkier texture.) Set aside.
Combine the chopped almond bark and sweetened condensed milk in a saucepan over low heat. Stir continuously until the mixture is smooth and the almond bark fully melts, about 5-6 minutes.
Remove the saucepan from the heat. Fold in the chopped Oreos, reserving about 1 cup for topping. (Avoid adding the cookie crumbs for a cleaner-looking fudge.) Mix gently to make sure the cookies are evenly distributed.
Pour the mixture into the prepared baking dish. Spread it evenly using an offset spatula.
Sprinkle the reserved Oreo pieces over the top, pressing them lightly into the fudge.
Refrigerate for at least 1 hour or let it set at room temperature for 2-3 hours until completely solid.
Once set, lift the fudge out using the parchment overhang. Cut into squares and enjoy!
Notes
Use low heat: Melting the chocolate over low heat prevents burning and ensures a smooth mixture.Keep stirring: Continuously stir while melting to avoid scorching at the bottom of the pan.Proper chilling: Let the fudge set completely before cutting for neat, clean squares.No crumbs: Stick to adding Oreo pieces to the fudge—skip the crumbs, or the fudge might lose its clean, pretty look.