The 33-year-old Sydney IT consultant attempted to create a lustful dessert but instead dished up something resembling roadkill when his white chocolate and rose water mousse cake collapsed seconds before presentation.

The damage was so bad, Daddia was unable to extract the baking paper from the white chocolate sludge.

He later copped a hiding from judge Matt Preston who warned him against becoming arrogant.

"People talk about you as being one of the best cooks in the competition and I think you believe you are as well," Preston said.

"The problem is, this is not the first time you have failed to deliver. Do it once and we go 'Okay, you've had a problem.' Do it twice and we start questioning your ability to organise yourself in the kitchen...You have to plan better."

Daddia, who has survived eight eliminations, made the mousse cake after choosing lust in last night's seven deadly sins-themed challenge.

Each of the contestants had to create a dish that represented one of the sins and give a story explaining their decision.

Top of the class was youngest competitor Callum Hann, 20, whose gluttony-themed dessert was labelled "brilliant" by judge George Calombaris.

Science graduate Alvin Quah, 35, also impressed with his "greedy" caramelised pork belly and saffron rice.

Daddia was powering until the last five minutes, when he struggled to cut the cake base and then realised the mousse topping hadn't set. Judge Gary Mehigan described the presentation as "a disaster."

"The sad thing about it is ... the flavours in there are really stunning," Mehigan said.

Daddia later admitted he had chosen too complicated a dish to serve up within the 90-minute deadline.

"It's the worst mistake I could have made," Daddia said.