On The Great British Bake Off (The Great British Baking Show in America), the technical challenges are some of the most dreaded by the contestants on the show. Not known for being easy, the Great British Bake Off recipes are sometimes so difficult that no baker can truly master them.

Judges Paul Hollywood, Pru Leith, and Mary Berry often concoct elaborate and obscure recipes meant to challenge the bakers and test their ability to adapt and think on their feet. However, there have been technical challenges that stump even the most talented contestants.

Related: Top Chef: 10 Things The Show Could Borrow From The Great British Baking Show

For every technical challenge, the bakers are ranked from worst to best, but sometimes none of the contestants can get it done, and their final products are a big mess. These are some of the technicals that had bakers scratching their heads and cringing as the judges inspected their work.

Tennis Cake - Series 6 Week 7

Great British Bake Off image showing a Tennis Cake

During Victorian Week, the bakers were tasked with whipping up one of the most difficult cakes of any Great British Bake Off season—the tennis cake. The recipe comes from the 1890s and is a rich fruit cake decorated with royal icing to resemble a tennis court, complete with net and tennis rackets. All of the bakers struggled and none of them really nailed it. From underbaked cakes to neon green fondant, this technical challenge was a bust.

Campfire Pita - Series 9 Week 10

Great British Bake Off Pita

During the series 9 final, the last three bakers were tasked with making pita bread outside over hot coals. None of the bakers had any experience with this method of cooking, and even Paul admitted “the temperature is going to be extreme.” High heat kills yeast, so none of the bakers’ pita puffed up and achieved the bread’s signature pocket. The contestants ended up scraping off whatever burned bits they could and prayed for the best.

Maids of Honour - Series 10 Week 4

Great British Bake Off Maids of Honour

This pastry, which dates all the way back to the Tudors, is one of the weirdest and worst recipes in Great British Bake Off history, and it was fair to say that none of the bakers had heard of them. Maids of honor are puff pastry tarts filled with lemon curd and “curd cheese” which looked awful. The contestants called the curd cheese mixture “vile” and “disgusting,” and nobody’s final product was up to the judge’s standards.

Sussex Pond Puddings - Series 11 Week 8

Great British Bake Off Pond Pudding

The bakers of series 11 were just as baffled by the Sussex pond puddings as viewers. The steamed suet puddings were popular in the 1700s and are filled with butter, sugar, and a whole lemon. All of the contestants struggled with the difficult puddings, mostly when it came time to remove them from their molds. None of the bakers were able to extract both of their puddings intact, and the bulk of them were an underbaked goopy mess.

Flaounes - Series 6 Week 6

Great British Bake Off Flaounes

Flaounes are a cheese-filled pastry from Cyprus that none of the bakers had ever heard of, and even judge Mary Berry called it their “toughest challenge yet.” Though they seemed straightforward on paper, the pastries contained two unique flavors—mastika (crystalized tree resin) and mehlebi (ground sour cherry pits)—and Paul didn’t provide any details about either of them. Though many of the bakers’ flaounes tasted fine, they all looked terrible.

Torta Setteveli - Series 9 Week 9

Great British Bake Off Torta Setteveli

Also called seven veils cake, judge Pru said she was “asking for the near impossible” with the torta setteveli technical challenge. The complex cake is comprised of seven layers—two chocolate sponges, hazelnut bavarois, praline base, and chocolate mousse, all topped with a chocolate mirror glaze. The bakers gave it their best effort but none of their cakes looked very good, and the mirror glaze and complicated layers tripped everyone up.

The Great British Bake Off contestants have been tasked with whipping up some truly diabolical recipes for their weekly technical challenges. However, it’s the effort that counts, and for these recipes, the bakers really gave it their best shot.

Next: The Great British Baking Show: 8 Shadiest Moments