His dresses have been worn by Jennifer Lopez, Taylor Swift, Beyonce Knowles and other celebrities.
Wedding Cakes and Sugar Flowers has a wide international circulation and more than 500,000 Facebook followers.
Mrs Mitchell's cake creations are in hot demand and tutorials on how she created some of her taste sensations have also featured in UK magazines.
Married to Kiwi-born property developer Anton Mitchell, Mrs Mitchell has an arts degree from the University of Culture and Arts, Kazan, Russia, and after graduating worked in a public-relations role at the Ministry of Trade in Russia.
The owner of Gulnaz Mitchell Cake Design said she specialised in wedding, birthday and anniversary cakes, and only used the best fresh ingredients.
The mother-of-three said she originally started making cakes for friends and family.
"But the real turning point was when my oldest daughter was diagnosed with coeliac disease, which is an intolerance to gluten, and Sophia has very high intolerance," she said.
In order to cater for Sophia's dietary needs, Mrs Mitchell created a gluten-free cake for the youngster's fourth birthday and never looked back.
Predominantly self-taught, Mrs Mitchell initially learned cake design techniques by watching YouTube videos and reading books.
"I never thought designing cakes would become my passion. But I have definitely found my real passion in life. I even dream about cake designs. Most of my friends and my mum were very surprised, as I had never really been into baking in the past," she said.
Mrs Mitchell never repeats a design and some of her intricate creations can take days to complete.
"One of my friends, who is an accountant, told me they couldn't understand how I would have the patience to do this. But their passion is working with numbers, which would make me fall asleep.
"My passion is cakes, and when I'm creating one I sometimes can easily lose track of the time."
