Chill a deep bowl and the rotary or whip beater of a mixer for at least 10 minutes.
Put cream cheese in bowl and mix on high speed with rotary or whip beater until cheese is spread around base of bowl. With mixer on high speed, pour cream down the side of the bowl (not into beaters) into the cheese, slowly enough that the cheese stays thick and forms ridges like stiffly whipped cream as you beat it; scrape sides of bowl as necessary.
When all the cream is whipped into the cheese, turn off mixer. Add lemon peel, lemon juice, and powdered sugar to taste; mix at medium speed to blend.
Nutritional analysis per tablespoon.