Correct spelling, explanation: during is a preposition. Before putting it in a sentence, always remember the correct spelling, which is really simple and doesn’t contain any double consonants. Durring is just an error and the only proper version of this word is during.

Definition of during:
preposition, throughout the course or duration of
I lived with my parents during childhood.
My grandfather died during World War II.

Incorrect spelling, explanation: this form is a mistake because nothing in the etymology indicates that the word during should be spelled with a double -r consonant. Its spelling is really simple. Therefore, durring is an incorrect form and the correct one is during.

Incorrect spelling

Incorrect spelling