Notre = our (singular noun follows) leur = their (singular noun follows) nos = our (plural noun follows) votre = your (singular noun follows)
Since the noun following the possessive adjective is "pâtisserie préférée" (fém. pl.), we can eliminate nos. Futhermore, (our) is in brackets, that eliminates leur and votre.
What is left is "notre", which agrees (singular) with the noun following, and also it means "our", as required.
Je vais jouer au ping-pong tu vas jouer au ping-pong il va jouer au ping-pong nous allons jouer au ping-pong vous allez jouer au ping-pong ils vont jouer au ping-pong
