There are umpteen ways to do this. They are:
Make your bakery products genuinely more flavorful and aromatic.
Try to introduce a special bakery product at least once a week to keep your customers interested in your service.
Keep them updated on their orders via push notifications on your app.
Give free samples to people to give them a taste of your quality of products and service.
Promote your products and service appropriately and effectively on various popular social media platforms.
Conduct in-app surveys among your customers. Take their suggestions and feedback positively and sincerely try to better the quality of your products and service.
Offer attractive discounts and loyalty programs on your app to retain your existing customers.
Offer neat and attractive packages because everybody loves a treat to the eyes and it speaks volumes about your professionalism.