Sugar n thyme.
Caked me away by Yashaswani is one option if you're in South Delhi. Your location is important too. Every corner of Delhi has a home baker that would love to customize cakes.
every bakery allows customisation of cakes .
For god's cake has awesome desserts and it is my personal favorite.
Fairy in my oven is pretty good
Try For God’s Cake, its one of the best bakery for customised cakes even cupcakes over here is amazing to have😋✅