Short answer. Yes, and how far it is cured depends on who ratifies. Under Article 1407, if the parent or guardian of one minor ratifies, the contract is treated as if only one party were incapacitated. If the parents or guardians of both minors ratify, the contract is validated from the very beginning.
What the law says
In a contract where both parties are incapable of giving consent, express or implied ratification by the parent, or guardian, as the case may be, of one of the contracting parties shall give the contract the same effect as if only one of them were incapacitated. If ratification is made by the parents or guardians, as the case may be, of both contracting parties, the contract shall be validated from the inception.
Civil Code, Article 1407 — Both Parties Incapable. Read the full provision →
Starting point: a contract of two incapables
When both sides to a contract cannot give valid consent — here, two minors — the agreement is not on solid ground. A contract where both parties are incapable is unenforceable, meaning a court will not compel performance of it as it stands. But unenforceable is not the same as dead. Article 1407 provides a path to cure the defect through ratification by those who stand in for the minors, namely their parents or guardians. The article's whole function is to explain how far that ratification repairs the contract, depending on whether one side or both is confirmed.
Ratification by one side
If only one minor's parent or guardian ratifies — expressly or by implication — the article gives that act a specific effect: the contract is treated as if only one of them were incapacitated. In other words, curing one side's incapacity does not make the contract fully valid; it upgrades it to the status of a contract with a single incapacitated party, which is voidable rather than unenforceable. The still-uncured minor's side remains a weakness the law recognises, and the contract can be challenged on that footing. One ratification improves the contract's standing without perfecting it.
Ratification by both sides
The complete cure requires both. Where the parents or guardians of both contracting parties ratify, the contract shall be validated from the inception. This retroactive effect is important: the contract is not merely valid going forward but is treated as having been valid from the moment it was made, as though the incapacity had never clouded it. So the outcome you are asking about is fully achievable — two minors' contract can be made good — but only when the representatives of both are on board. Anything less leaves a residual defect that the law still recognises.
What ratification cannot do
Ratification fixes the problem of incapacity; it does not save a contract that is void for some other reason, such as an unlawful object or cause — those defects cannot be cured by confirmation at all. The article also assumes ratification by the proper person, the parent or guardian acting for the minor, not by the minor alone. And it addresses the effect of ratification on validity; it does not compel anyone to ratify. Whether to confirm the contract is a decision for the representatives, made in the minor's interest, and until they act the contract keeps the weaker status the article describes.