The fourth series of MasterChef Australia premiered on Sunday, 6 May 2012 at 7.30pm on Network Ten.
 Judges George Calombaris, Gary Mehigan and Matt Preston returned from the previous series.
 After the first week in Melbourne, the competition took the contestants to places nationally, such as Kangaroo Island and Tasmania, as well as the international destination, Italy.
 It also featured a number of guest chefs, including Jamie Oliver, Rick Stein and Buddy Valastro.
Bartolo "Buddy" Valastro Jr. (born March 3, 1977) is an American celebrity chef, entrepreneur, and reality television personality of Italian heritage.
 He is the owner of Carlo's Bakery, as well as the face of Buddy V's Ristorante.
Peter Gilmore (born 1968) is an Australian chef.
 He is the current executive chef of Quay, which has been included in The World's 50 Best Restaurants since 2009.
 and the newly opened Bennelong, at The Sydney Opera House.
 He sometimes guest stars in Masterchef Australia, where his signature dessert the "Snow Egg" was touted as one of the toughest Masterchef challenges.
 He is now the executive chef at Bennelong.
Kirsten Tibballs (born 1973) is a pastry chef and chocolatier based in Melbourne, Australia.
 Tibballs has represented Australia at world championships and as a judge for global competitions.
 In 2002 Tibballs founded Savour Chocolate and Patisserie School in Brunswick, Melbourne.
 Tibballs is the author of two cookbooks, a regular contributor to pastry publications and has featured on several television shows including MasterChef Australia.
 As one of the most followed female pastry chefs on Instagram, Tibballs is regularly referred to as the ‘Queen of Chocolate’ due to her contribution to the chocolate industry.
MasterChef Asia is a regional competitive cooking game show based on the original British show MasterChef.
 The show is produced by Lifetime Asia.
 A total of 15 home cooks from various regions across Asia (China, India, Indonesia, Malaysia, Philippines, Singapore, Taiwan, Vietnam) competed in the first season of MasterChef Asia.
 The show is judged by Hong Kong-born, culinary chef Susur Lee; 3-Michelin starred chef Bruno Ménard; and Singapore-born Audra Morrice, a MasterChef Australia finalist.
 From the MasterChef kitchen to off-site and overseas challenges, the 15 episodes will culminate in one home-cook winning the title of the first ever MasterChef Asia.
Junior MasterChef Australia is an Australian competitive cooking game show.
 It was a spin-off of "MasterChef Australia", itself an adaptation of the British show "MasterChef", and featured contestants aged 8 to 12.
 The first season of the show began production in July 2010 and included 50 contestants.
 Over 5,000 children from around the nation auditioned for the series.
The second series of Junior MasterChef Australia premiered on Sunday, 25 September 2011.
 Auditions closed on 6 May 2011; children who will be aged between eight and twelve years old during the period from 13 June to 28 October 2011 were eligible.
 The judging panel consists of Gary Mehigan.
 George Calombaris, Matt Moran and Anna Gare.
 Matt Preston, who has been involved in every incarnation of the "MasterChef Australia" series up to this point, will be taking a step back from the series (also declining a spot as a guest judge on the U.S. version of "MasterChef"), stating he wants to concentrate on his duties as a food critic.
 He will be replaced by Matt Moran.
MasterChef Asia (season 1) is a regional competitive cooking game show based on the original British show MasterChef.
 The show is produced by Lifetime Asia.
 A total of 15 home cooks from various regions across Asia (China, India, Indonesia, Malaysia, Philippines, Singapore, Taiwan, Vietnam) competed in the first season of MasterChef Asia.
 The show is judged by Hong Kong-born, culinary chef Susur Lee; 3-Michelin starred chef Bruno Ménard; and Singapore-born Audra Morrice, a MasterChef Australia finalist.
 From the MasterChef kitchen to off-site and overseas challenges, the 15 episodes will culminate in one home-cook winning the title of the first ever MasterChef Asia.
Shawnae Marie Dixon is an African-American professional chef, cookbook author, and owner of "SayGraceNYC".
 She was born Shawnae Marie Mosley McCombs in Staten Island, New York in 1976.
 Today Dixon is sought by celebrity clients worldwide to cater, host, and prepare her signature dishes for both private and public settings.
 Dixon speaks and appears as an celebrity chef for many syndicated radio and television programs in the U.S.
 Her first book, "With this Plate I Thee Wed..
."
, with a foreword by Lamont Renzo Bracy, is set to be released in 2017 by Amazon Publishing.
 In addition to touring and book signings, Dixon is a regular guest chef on numerous TV shows with an reoccurring role as guest chef on Jack Thriller Party and Bullshit show.
Surjan Singh Jolly, fondly known as Chef Jolly, is the Executive Chef at JW Marriott, Bengaluru.
 He started his career in 1993 at Taj, New Delhi as the Chef de Partie.
 Chef Jolly has been in the hospitality industry for over two decades.
 His recent achievements include having his own show on Zee Khana Khazana titled "Ab Har Koi Chef".
 He was also chosen as the Head Chef for Paris Hilton when he visited India and has been the Guest Chef on the world-renowned reality television show, MasterChef India.
 He was judge on the first season of Junior Master Chef India.

Question: MasterChef Australia's fourth season included a guest chef who is the owner of what pastry shop?
Answer: Carlo's Bakery