Maraschino cherries from a jar leave a little —well, a lot, actually— to be desired. The highly processed, artificially flavored and dyed little lumps bear only a passing resemblance to real, fresh cherries. The good news is you can make much better ones yourself, and at a fraction of the cost of the fancier type imported from Italy.
I found a recipe on chow.com and made a couple minor changes. The first thing you will need is, of course, cherries! For truly authentic maraschino cherries you would need sour Marasca cherries, but these are pretty difficult to find. Fortunately, you can substitute more common varieties found in the U.S. such as Bing (that's what I used). For this recipe you will need one pound.
I didn't want to spend the money to buy a bunch of vanilla beans when I only needed half of one, so I substituted a half teaspoon of vanilla extract. I doubt it makes a noticeable difference, but go ahead and use half a vanilla pod if you're fancy like that.
The third ingredient which you're not likely to have in your cupboard already is maraschino liqueur; the preferred brand is Luxardo. Your grocery store probably doesn't have it, but I found it easily at a store that sells beverages… and also more things…
The only other ingredients you will need are water and sugar (or sugar substitute, I used Splenda and it works fine). You will also need some gear: a good cherry pitter (try Oxo), a quart jar that seals tightly (check Amazon for Fido flip top jars), and a sieve or strainer. Be warned that pitting cherries is messy and will splatter juice all over your favorite shirt, so an apron or a top you don't care about is highly recommended.
Now we are ready to get to work. First wash and pit your pound of cherries, but don't throw out the pits, we're going to use those too. Set the cherries aside, put the pits in a zip top bag, and wrap it with a kitchen towel. Get out your meat mallet or frying pan or something else heavy and smash those pits to bits. Now put your cherry pits, vanilla (1/2 teaspoon of extract or half a pod and its seeds), 3/4 cup of sugar (or Splenda), 1/4 cup of water in a little sauce pan. Mix it all together and bring it to a boil. Make sure all your sweetener dissolves in the water. Take it off the heat and wait for it cool to room temperature (about 40 minutes).
Once your syrup has cooled, strain out all the pit bits and the vanilla seeds and pod if you used that. Hang on to that pod if you have it. Add one cup of maraschino liqueur to your strained syrup and stir to combine. Next, pour your pitted cherries into your quart jar, and if you have a vanilla pod, stick it standing straight up in the middle. Pour your syrup/liqueur mixture over the cherries and make sure they are all submerged.
Now comes the hard part. Seal up your jar, put it in the refrigerator and wait… at least five days. After they've had some time to marinate, your cherries will be ready to garnish Manhattans, Rob Roys and many other delicious cocktails. Note that the alcohol is not cooked off, so these cherries are just for adults.
My guess is that once you've made your own, (somewhat) authentic Maraschino cherries, you'll never want to bother with those sickly-sweet, red dyed, processed little lumps ever again.