Forger's Foundry

The mana added by Forger's Foundry can be spent on anything, not just instant and sorcery spells with mana value 3 or less.

You choose which spells (if any) to cast as Forger's Foundry's last ability resolves. If you do, you do so as part of the resolution of that ability. You can't wait to cast them later in the turn.

You cast the spells one at a time as Forger's Foundry's last ability is resolving, choosing modes, targets, and so on. The last spell you cast will be the first one to resolve. Ignore timing restrictions based on the cards' types. Other timing restrictions, such as "Cast [this spell] only during combat," must be followed.