You hold: ♠ 742 ♥ 76 ♦ AQ ♣ 1065432

When in doubt, support partner. It could be easier for your side to make eight tricks in spades than to take seven tricks against one no-trump, especially since you have a bit of shape. The opponents may not be able to penalize you even if it should be possible in these days of takeout doubles! Your call of two spades also takes some cheap actions away from your left-hand opponent.