Using Magic to influence a person (such as an ex) is not always recommended. Most of the time, it’s unethical to interfere with someone’s free will or cast spells on a person without their permission.
On the other hand, Magic has been used for this very purpose (love, marriage, loyalty) for thousands of years. So I considered important to include a honey jar spell in the Love Spells page. 
However, you’ll notice that most of the spells are focused on self-love and/or opening up to love, without targeting anyone directly.
I recommend that you cast a spell for clarity, for example, to identify what caused the relationship to end, to determine if there was anything that you could do or say, and to work out whether this situation might be positive for you in the long run.
If you have done this and are set on doing a honey jar spell, I suggest that you add to the end of your incantation:
“For the greater good of everyone involved, and harm no one!”
And follow the instructions on the spell recipe.
Good Luck and Blessed Be! 