Sugar-free vegan cake for toddlers?

Looking for a cake recipe that is:

- vegan

- no sugar (though a little maple syrup would be fine)

- relatively easy/simple

- only ingredients that can be found in a normal grocery store

for my toddler's 2nd birthday party.

I made this twice last year and it was decent, but I tried making it yesterday for his family-party and it didn't work out. So I don't want to risk messing it up again for his friend-party. https://pickyeaterblog.com/healthy-smash-cake/#recipe

Thanks so much for any suggestions.