Hi Rabbi Bartfeld,
I hope all is well.
Two questions the Rabbonim in LA wanted to know Rav Miller’s position:

Q1. Liquid Chocolate (not hot) that is poured on Ice Cream and when it comes in contact with the ice cream it hardens. Is there a molid problem, the only tzad kula might be that it has a shem ochel beforehand, however, it is sof sof liquid form.

A. Mishna Berura (118: 101) explains that the opinion of the Shuchan Aruch is to permit placing a cold kugel close to a permitted heat source, even though the solidified cold gravy it contains will melt. The reason is that it is not similar to the prohibited crushing and grating of ice (O.H. 320: 9) as it is not done here “beyadaim” in an active act, rather it turns liquid by itself when it warms. Therefore, he argues, the rabbinical prohibition of nolad, or creating something new does not apply. However Remoh (ibid,) rules that one should be stringent unless there is need.
Some Poskim permit making ice cubes or placing already made ice cream in the freezer on Shabbos. (Piskey Teshuvo 321; 120 Although Tzitz Eliezer (6: 34) rules stringently on ice cubes, he permits placing liquid foods in the fridge that will solidify when cold. Minchas Ish (2; 59 n. 116) quotes Poskim that permit solidifying edible foods that continue to be edible when hardened, similar to the liquid chocolate poured on ice cream.
Horav Shlomo Miller Shlit’a added as another reason to be lenient, the fact that the now solid chocolate will shortly revert to its liquid state, when the ice cream melts.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a