[AmityvilleHams]

Not sure on exact amounts,but you could use pumpkin(plain pureed with water)and hamster safe flours to make this.The flours would need to be corn and wheat free if they'd potentially get shared with dogs in any way,but there are tons of flour options that work for hamsters and dogs such as rice flour(brown or white,brown tends to be preferred but white is just fine if you can find that easier,make sure there are no additives as with any ingredient),plain coconut flour,plain oat flour,or in some cases a legume based flour(just check that they're hamster safe,these also might have potential added flour sources such as sorghum,again with dog-shared items there must be no wheat,corn,or wheat relatives such as spelt).

You could also add flax seed,shredded unsweetened coconut flakes,and other safe toppings to make it even more cake-like.An icing made from a high quality natural nondairy yogurt(no added sugars or artificial sweeteners such as maltodextrin/dextrose/sorbitol/sucrose/fructose/etc,no artificial or unspecified preservatives or "E&C approved" preservatives/antioxidants which can include BHA/BHT/ethoxyquin which are known to cause cancer,etc)and dyed with natural fruit based dyes could work too,and if you have a few extra pieces of safe fruit not used for the dye making you could use them as toppings also!