How to call OnCollisionEnter2D once when hitting multiple objects?

I have a bullet object that when it collides with an enemy it Instantiates an explosion prefab but when two enemies are on top of each other the method is called twice and spawns two explosions so is there a way to detect multiple enter collisions or call the method once?

Here’s the code for the bullet

public GameObject explosion;

    private void OnCollisionEnter2D(Collision2D col)
    {
        if (col.gameObject.CompareTag("Enemy"))
        {
            gameObject.SetActive(false);
            EXPLOSION();
        }
    }

I think you can put a bool on the enemy to check if it has already spawned an explosion or not.
You can also create auto-reset the bool after a certain amount of time has passed to let another explosion happen.

if (col.explosionAlreadySpawned == false){
    SpawnExplosion();
}