It is a combination of two Energy Spheres.
The first use of this technique in the series is from Salt and Mustard when fighting on The Lookout: the two Spice Boys combine two red energy spheres (their Salt Break and Mustard Break) and fire it at Gohan. In the same Garlic Jr. Saga, Spice and Vinegar create their Sugar Ignite and Vinegar Cannon for a team attack, but are interrupted by Piccolo when they combine their energy spheres.
In Dragon Ball Z: Super Android 13!, Android 15 and Android 14 use the attack to blow up the building where Goku and his family are at. It was strong enough to distort the gravity, causing everything above to levitate before the explosion.
Goku and Vegeta also use a similar attack twice against Super Buu: the first is used to try counteract the Ultimate Cannon launched by Super Buu, and the second is used to blast one of his clones in the dimension existing within Buu's own body.
Goku Black and Future Zamasu use a combined Black Power Ball, Holy Light Grenade, several times in Goku and Vegeta's travels to the future. First shown when combined to finish Future Trunks and Goku. Fused Zamasu also uses this attack as well.
In the anime, during their fight to test the arena of the Tournament of Power, the God of Destruction Liquiir combines two energy balls into one that clashes with Arak's Energy Barrage and Iwan's Energy Slash Wave.