I came across this expression in the TV series Blacklist and found it quite interesting. It's an American expression used to emphasise one's certainty. Here you can find an interesting article explaining the origin of this phrase: <a href="http://www.todayifoundout.com/index.php/2015/06/origin-phrase-dollars-donuts/" rel="noopener noreferrer" target="_blank">http://www.todayifoundout.com/index.php/2015/06/origin-phrase-dollars-donuts/</a>;. It also states that there were similar expressions like "dollars to dimes", "dollars to dumplings", "dollars to cobwebs" and "dollars to buttons" but apparently "dollars to doughnuts" is the one that caught on.

If I were to translate this phrase to German I'd either say "<em>Da kannst du Gift drauf nehmen</em>" (You can take poison on that) or "<em>Das ist so sicher wie das Amen in der Kirche</em>" (It's as certain as the amen in church).

Are you using "dollars to doughnuts" or a different expression to express your absolute certainty in English? Are there similarly colourful expressions in your native or target languages, that you'd use to translate phrase?