"To double a recipe" is the normal expression in English. It means to make twice as much by doubling all the amounts. I've never had the impression that this is an idiom. It follows from the literal meanings of "to double" and "recipe".
A quick check shows that a similar expression exists in German. It seems like a perfectly reasonable thing to say in Esperanto.
The dictionaries give the following definition for 'recepto': "Skriba klarigo pri preparado de manĝaĵo, trinkaĵo aŭ ia teknikaĵo". The double of "skriba klarigo" is "du skribaj klarigoj", so that is an idiom (even though a rather reasonable one, I think). What you really double is the quantities (of ingredients).
There is a danger in being a slave to the dictionary. A recipe includes a list of ingredients and when you double a list and follow it twice, you have twice as much. I'm not going to quibble over the definition of "idiom" - I'll just repeat what I said before without using the word - The meaning of "to double a recipe" follows from the meaning of "double" and "recipe" and as far as I know, this is a universal concept.
If you can give us a list of languages where a literal translation of "to double a recipe" doesn't work, I will reconsider my thought on this, but for now, I would say that "duobligi recepton" is good Esperanto.
In French, we rather say: "doubler les quantités d'une recette", "doubler les ingrédients", "doubler les proportions d'une recette", or "doubler les doses", than "doubler une recette". It is understandable, but a bit of a strange shortcut nevertheless, and it feels imprecise. Are you making the recipe twice in a raw or just doubling your quantities? Or are you meaning the cooking time? In Italian: "raddoppiare le dosi di una ricetta" also seems to be prefered to "raddoppiare la ricetta". I'm afraid I don't know how to check how any non-Indo-European language work here.