In a medium saucepan, combine the sweetened condensed milk and white chocolate chips over low heat. Stir continuously for about 5-7 minutes until the mixture is smooth and glossy.

Once smooth, remove from heat and stir in the peppermint extract. Divide the mixture in half and add semi-sweet chocolate chips to one half, stirring until melted.

Add a few drops of red food coloring to the white chocolate half and gently stir until desired swirl effect.

Line an 8x8-inch square baking dish with parchment paper. Pour the white chocolate mixture into the dish, smoothing it out.

Spoon dollops of the semi-sweet chocolate mixture on top and swirl together using a knife or skewer.

Sprinkle crushed peppermint candies over the top, pressing lightly into the surface.

Refrigerate for at least 2-3 hours or until firm, then cut into squares.