Q. When Yom Tov falls on Motzei Shabbos you make havdala at the end of the kidush adding the brocho of meorei haeish. Since you can’t light your regular havdala candle, because you can’t extinguish it on Yom Tov, should you make the brocho on the Yom Tov candles the way they are, join them together to create the avuka effect or light two matches? What is the correct procedure?

A. Shulchan Aruch (O.H. 298: 2) asserts that it is best to use an avuka or lighted torch for the brocho of meorey haeish recited during havdala, although if one is not available you can still comply with one single lighted candle. (Mishna Berura ibid. 7.). There are different opinions as to what exactly constitutes an avuka.Mishna Berura (ibid. 8) rules that many wicks in one single wax candle do not create an avuka, since they are considered only as a single candle with a wide wick, as opposed to multiple wicks in an oil lamp. He also writes that it is better to use wax candles (ibid. 5.)
Poskim disagree whether it is better that the different wicksin the candles should come close, and the resulting flame should be connected (Magen Araham ibid.) or it suffices if they are two or more candles in close proximity (Piskei Teshuvos ibid.)
When Motzei Shabbos is also Yom Tov, Poskim convey different opinions as to what is best.
Many maintain that there is no halachic issue if you take two of the already lighted Yom Tov candles and bring the flames together or you just hold and approach one candle and incline it to the next, although some of the wax may spill. This could be considered as a prohibited causative extinction of a fire on Yom Tov, as you remove some of the wax fuel and shorten the life of the candle. However, many Poskim, permit this since there it is done without intention and it is only a Rabbinical prohibition. (Yisod Veshoresh Hoavodo quoted by Mate Efraim 600: 3, Mishne Halochos 8: 217, Beer Moshe 8: 184, Staipler Gaon ztl quoted in Orchois Rabbenu 2: 111, Yom Tov Sheni Kehilchoso 1: 53 quoting Horav Eliashiv zt”l.)
Other Poskim maintain that it is best to just bring the candles close to each other without touching. (Horav S. Z. Auerbach zt”l quoted by Yom Tov Sheni Kehilchoso 1: 14, Minhagei Chabad quoted by Piskei Teshuvos 514: 6.) Others sponsor the view that a minor should hold the candles together. Nitey Gavriel, Vayaged Moishe p.91.)
Horav Shlomo Miller’s Shlit”a opinion is that it is best if one just lights one match and places it next to a lighted candle and after reciting the brocho, he carefully places the lighted match on a plate, as was already done before when lighting the Yom Tov candles.

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