Step 1: Bake a square shaped cake and allow it to cool.
Step 2: Once it has cooled, fill it with peppermint buttercream (just add 1/3 cup finely crushed candy canes into my regular buttercream icing recipe). Also, frost your entire cake in regular buttercream icing.
Step 3: Now, cover your cake in light green marshmallow fondant.
Step 4: Arrange the round peppermint candies into square shapes on top of the cake. Stick them into place with some melted white chocolate or thick royal icing. Fill the space between them by sprinkling some crushed candy canes.
Step 5: To make the border around your cake, break mini candy canes irregularly. Brush melted white chocolate or thick royal icing to stick them into place.
And you are done!
I bet if you make this cake on Christmas, your guests will be blown away by its beauty!