First, Vegeta charges at the opponent, but stops right in front of them and places both of his hands on the opponent's chest. Then, he grins up at the opponent and charges yellow energy in his hands. Finally, Vegeta fires the yellow energy in the form of a massive energy wave against the opponent, inflicting a huge amount of damage.
Vegeta uses this attack against one of Babidi's henchmen, Pui Pui. Wanting to give Pui Pui the advantage, Babidi teleports the fighters to Pui Pui's home planet Zoon, which has 10 times the gravity of Earth. Pui Pui tries to attack Vegeta, only to be pummeled once again by the Saiyan prince, due to his training under 450 times Earth's normal gravity. As Pui Pui stands back up and attempts to attack again, Vegeta appears in front of him and blasts him with the Double Galick Cannon, destroying Pui Pui and winning the fight, although not before asking him if Pui Pui still thought he was bluffing (referring to Pui Pui's retort to Vegeta after the latter dismissed the gravitational force of Zoon's affect on him).
Appearance in Video Games
It appears Dragon Ball Z: Hyper Dimension under the name Dash Bomb. The technique is Vegeta's throw move in Dragon Ball Z: Ultimate Battle 22. The attack was named Double Galick Cannon in Dragon Ball: Raging Blast and Dragon Ball: Raging Blast 2, where it appears as one of Vegeta's Blast 2 attacks. In Raging Blast 2, there is a trick where you activate the attack and with enough distance, will not have the cutscene but the opponent will still be blasted.