that takes the cake (US), that takes the biscuit (UK)
idiom

- be the most outstanding in some respect, either the best or the worst

(The Free Dictionary)

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This phrase is used in situations where you think something is incredible or unbelievable, regardless if it's good or bad. It was originally used mainly to describe positive things or situations. After all, taking a cake - and eating it - is a good thing. That brings us to another expression - you can have your cake and eat it too - which means having something both ways.

Most experts believe the phrase "that takes the cake" originated with cake-walk competitions that were commonplace in the black communities of the southern United States in the 19th and early 20th centuries. The cake walk was a game usually held at local festivals in which couples dressed in their finest clothes and strutted around to see who was the most impressive. The winners were often awarded a cake as the prize.

The underlying concept of the phrase goes back much farther however. In the 5th century BC the Greeks used "take the cake" as a symbol of victory. In 420 BC Aristophanes wrote a criticism of the powerful Athenian politician Cleon: "If you surpass him in impudence the cake is ours."

Here are a few more common "cake" expressions:

- to have one's cake and eat it = auf zwei Hochzeiten tanzen; alles auf einmal haben wollen
- cherry (icing) on the cake = das Sahnehäubchen; das Tüpfelchen auf dem I
- that's a piece of cake = Das ist einfach, Das ist leicht, ein Kinderspiel

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SYNONYMS

that's incredible, that's unbelievable, that's outrageous

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Practice OWAD in a conversation:

"Their attempt to undercut our prices really TAKES THE CAKE! We'll need to call a meeting immediately!"