Prepare an 8x8 inch square pan by lining it with parchment paper or aluminum foil, making sure to leave some overhang on the sides. Lightly coat the paper or foil with cooking spray. Next, place your candy canes into a sealed plastic bag and gently crush them into small pieces using a rolling pin – it's a great stress reliever!
In a microwave-safe bowl, combine the white chocolate chips, sweetened condensed milk, and butter. Microwave the mixture in short 30-second intervals, stirring thoroughly after each one, until everything is smooth and fully melted. This usually takes just 2-3 minutes. Stir in the vanilla extract until it's completely blended.
Pour the creamy fudge mixture evenly into your prepared pan and smooth the top with a spatula. Sprinkle half of the crushed candy canes over the surface. Cover the pan with plastic wrap and place it in the refrigerator for at least 2 hours, or until the fudge is firm.
Once chilled and firm, use the parchment paper overhang to easily lift the fudge out of the pan. Place it upside down on a cutting board (this means the sprinkled candy canes are now on the bottom). Use a sharp knife to slice the fudge into your desired square sizes, yielding between 16 to 32 pieces. Finally, sprinkle the remaining crushed candy canes on top of the fudge, gently pressing them in if you like. Serve and enjoy this festive treat at room temperature!