Parent and Child Rasengan

The Parent and Child Rasengan is cooperation ninjutsu where two shinobi — a parent and a child as the name suggests — combine their Rasengan to create a massive one.

Naruto and Minato's Version
Naruto and Minato, while both in Tailed Beast Mode, and Naruto in Sage Mode as well, collaboratively create a Rasengan of their chakra avatar's size, then ram it into the target. This attack was strong enough to push back Obito Uchiha as the Ten-Tails' jinchūriki.

Naruto and Boruto's Version
Boruto starts off by generating a tiny Rasengan. Clasping Boruto's hand, Naruto then adds his own chakra to the Rasengan, forming a gargantuan sphere, which dwarfs both of them in size. Boruto used this technique to kill Momoshiki Ōtsutsuki, on top of obliterating his Rinnegan-enhanced Rasengan and Tailed Beast Ball, as well as a God Tree.

Trivia

 * Though clearly not a normal Rasengan, it was simply called the Rasengan in the Boruto manga and Boruto: Naruto the Movie.
 * In the novelisation of Boruto: Naruto the Movie, the Rasengan that Naruto and Boruto created functioned the same as Boruto's Vanishing Rasengan on a more powerful scale.
 * While transferring his chakra into Boruto's Rasengan, Naruto was also able to somehow convey his memories of his past, detailing his suffering and struggles while fulfilling his dream to become Hokage. ''