I think that would be fun, I been wanting build(design)-a-cake. Choosing batter/cake flavour, icing colour/flavour and garnish/addons, etc.
Honestly, they could double down on food/dessert/drink creation/recipes as a part of the game or in a game pack. I loved Café World (old zanga app game), and I really like the simple living aspect of Cottage Life, and the mixer (also waffle maker and pizza oven) in Home Chef Hustle and having that in an active career, in depth business or even just home cooking added steps/uniqueness—could add complexity, fun and artistic touch to the game.
They could also fixed Dine Out and even improve upon Cool Kitchen so it could be used in business setting, and Simmers if they want to could basically have Simulation cooking/baking gameplay as a primary focus (or keep it a casually used feature for on home lot menu).
It also could be almost indefinitely expanded on. As cuisines from various regions, customizations and ingredients can be added via packs and updates.