Wash and stem the cherries and pit cherries.
Prepare your jars and lids following manufacturer's instructions
After pitting, put the cherries and 2 cups of the sugar in a large pot. Let this sit for about 15 minutes until the juices begin to flow.
Attach a candy thermometer to the side of the pot. Make sure the bulb is covered with juice.
Stirring frequently so nothing burns, bring to a boil over medium high heat. Once it starts to boil, continue stirring until the mixture reaches 212°F.
In a small bowl combine the rest of the sugar and the cornstarch and stir into the boiling cherries.
Add the almond extract and stir continuously as the temperature comes back up to 212°F.
Remove from heat.
Ladle the hot filling into one hot jar at a time, leaving a 1/2 inch headspace. Make sure you get out any air bubbles with your bubble remover thingy.
With a clean damp cloth, wipe the rim of the jar to make sure there is nothing sticky on it. Add the lid and attach the ring finger tight. Fill and close the remaining jars.
Place the jars in a water bath canner and process for 15 minutes for pints or 20 minutes for quarts.
Remember to adjust processing time for your altitude.
After processing, remove the jars from the canner by lifting them straight up out of the water and place them on some towels out of drafts.