Volcanic Kitchens is a collection of more than 165 recipes representing the community, from pasta made from scratch, favourite baking recipes, traditional family favourites and an exotic mix from the many ethnicities that make New Zealand home.
Henri says it is their fourth book and they have won a New Zealand category each time.
"It's always nice to get the recognition."
She thinks this latest cookbook has done well in the "Easy Recipes" category because it is the community's favourite recipes.
"It's what people enjoy cooking at home. They are tried and proven recipes people cook at home and that's what makes it special."
Gerhard and Henri are also aiming to raise at least $20,000 for Rotorua Community Hospice through Volcanic Kitchens.
"There are quite a few businesses selling it on behalf of hospice and they will have a hospice sticker inside so people know they are contributing.
"This book is all about the Rotorua community and the diversity of the people, landscape and environment.
"For us it's a story that starts with the community contributing and finishes by the community benefitting from it at the other end too."
The Gourmand World Cookbook Award honours the best cookery and beverage books in the world in various categories.
It was founded by Edouard Cointreau in 1995 as the World Cookbook Awards and changed its name In 2001.
Thousands of books from more than 150 countries are submitted every year. The books are divided into categories by an international jury made up of four to five members.