Feat: One-Inch Punch

You put all your force into a single mighty, carefully controlled blow. Make an unarmed Strike. If you spend two actions and this Strike hits, you deal an extra die of weapon damage. You can instead spend 3 actions to perform an even more powerful attack, dealing a second additional die of weapon damage on a hit.

If you're at least 10th level, the number of additional dice you add from this feat doubles, for a total of 2 additional dice if you spend 2 actions or 4 additional dice if you spend 3 actions.

If you're at least 18th level, the number of additional dice you add from this feat triples, for a total of 3 additional dice if you spend 2 actions or 6 additional dice if you spend 3 actions.