Adding Sugar crystals to Ice Cream Cake

My daughters 40th birthday is coming up in 2 weeks and she has asked me to make a aqua colored bling cake, full of sparkle for a party. The problem is she only likes ice cream filled cakes which I normally frost in a whip cream base icing. I think this would cause the sugar crystals and dragrees to dissolve. I think if I cover it in fondant then cutting will be an issue as the fondant will crack. Any ideas or suggestions would be very appreciated. I have looked at the “rhinestone” tapes for the sides but I prefer the look of everything being covered in sparkle.