Next, I cut the chocolate into unevenly-sized slabs with my trusty metal paint scraper. This worked well because I took the chocolate out of the freezer while it was still ever so slightly pliable. Once cut, I peeled the slabs off the gladwrap, popped them back on the cold tray and put them back in the freezer to finish setting. When it came to applying them, I cut some of the bigger ones in half across the middle to get two shorter pieces that could be turned on their sides, and also trimmed the bottoms so they'd sit flat.
Then, I applied another layer of ganache to the cake (oh yeah. I did that for the previous cake too but I forgot to mention it, and now I CBF editing the post) and glued the white chocolate slabs onto the sides of the cake using more ganache. The next step was to pour a bag of M&Ms over the cake and press them down gently to make them stick. I usedthe mixed ones, which I suspect improves the overall look because the randommness of M&M sizes goes with the randomness of the chocolate height around the edge. One normal bag is just enough. I only ate two of them. Are you proud? :)