In weblio's entry about recommend (note: I can't understand the Japanese content), an example is given of "recommend" being followed by an infinitive:
She recommended me to try this oil for sunburn.
Is this valid English?
Yes, this is acceptable in all registers. Recommend may take a that, gerund, or infinitive complement:
An older use which appears to have virtually disappeared is the infinitive with prepositional dative:
You could also use "She recommended I try this oil for sunburn" or "She recommended this oil for sunburn". The latter is slightly ambiguous!