Maybe add some of the older toppings to a section of the shop, neither behind a paywall or in a section titled legacy Toppings, where people can choose wether or not to purchase the legacy toppings.
Obviously at a higher price.
And for older toppings like truffle since they were a season pass topping have those be a higher price. Like gems or something.
Either that or every so often have there be an event where you can collect older toppings by progressing through event quests.
And then a toggle switch for toppings where you can toggle which toppings would be used. If it’s not too much trouble.