Marshmallow mud cake

The night before the scrabble party there was another party, Lexi's birthday/Tara's farewell potluck party. A couple of weeks before I heard Lexi say that you wants to make the marshmallow mud cake from my sweet vegan but she can't because we can't get ricemellow cream here. So I decided to try to replicate it with the marshmallow making kit.

The kit had instructions for making marshmallow 'cream' or fluff. So I did that and was left with a quite firm jelly like texture, I followed the recipe in the book but added more 'cream' that it asked for and it come out great, both texture wise and taste wise. Although I later decided that maybe it wasn't marshmallowy enough so decided to use the 'cream' to make letters which we put on the cake. We put x's on it because Lexi is straight edge. And then used black writing icing to make a shadow around the letters.

While I was impressed with the icing, the cake itself was tiny. It barely rised in the oven and was so flat. I wonder if maybe the mixture should have been put into a 8 inch pan instead of 9 inch pan like it asked for, or if I did something wrong.