Prep for canning. Fill your water bath canner with water and simmer on the stovetop. Wash your jars with hot, soapy water. Transfer them to the water bath canner and simmer until the pie filling is ready. Place the lids and rings in a saucepan and simmer (do not boil).
Prep cherries. Bring a large pot of water to a boil. Destem and remove the pits from the cherries. Working in batches, blanch the cherries in the boiling water for 3 minutes and transfer them to a large bowl. Set aside.
Start syrup. In a large pot, add the sugar and clear jel. Stir to combine. Add the water.
Cook to thicken. Place over medium heat and allow it to thicken, stirring constantly. Continue until the mixture becomes bubbly. This process takes about 8 minutes.
Add juices and flavoring. Add in the lemon juice, vanilla extract, almond extract, and cherry juice (if using). Stir to combine. Allow the mixture to start bubbling again, stirring constantly. This takes about 2-3 minutes.
Add cherries. Remove the mixture from the heat and fold in the blanched cherries.
Fill jars. Using a canning funnel, ladle the cherry pie filling into the prepared jars, leaving a 1 ¼ inch head space.
Clean rims and screw-on lids. Clean the rims of the jars using a moist, clean towel. Add the lid and rings, tightening the rings until they’re fingertip-tight.
Process jars. Transfer the jars to the water bath canner, making sure the jars are fully submerged in water. Bring the water to a boil. Once boiling, set the timer and process quart jars for 35 minutes and pint jars for 30 minutes.
Rest. Turn off the heat, remove the lid, and allow it to sit in the water for 10 minutes.
Cool and check the seals. Remove the jars from the water bath canner and transfer them to a cooling rack or heat-resistant spot for 12-24 hours. After 24 hours, check the lids for a proper seal. Once a proper seal has been confirmed, remove the rings and store the jars in a cool dark place for up to 18 months or per your lids manufacturer's recommendations.
Notes
For a thicker pie filling, increase the clear jel to 1 ¾ cups.