Smash cake icing?

Kelly

So baby hasnā€™t had sweets yet, only natural sugars like fresh fruit. Iā€™m doing a smash cake with a muffin recipe he LOVES. Carrot, zucchini, banana, & oatmeal, I know heā€™ll prolly eat it all if I let him šŸ˜‚ Iā€™ll be doing a two tier 6 in cake. My question is what should I do for icing??? I donā€™t want it to have added sugar but understand if thatā€™s the only way to make it happen. Any mommas found a good recipe or alternative like a yogurt based frosting? Please share your ā€˜unsweetā€™ šŸ¤·ā€ā™€ļø ā€œfrostingā€. TIA and all suggestions/variations are welcome!