Wash the cherries. Stem and pit them, placing them in acidulated water as you work to prevent browning.
Place the fruit a batch or two at a time in boiling water. Let water return to the boil, then boil 1 minute. Get fruit out right away, and put in a covered bowl or pot to keep warm. Repeat until all fruit has been blanched.
Put the Clearjel in a very large pot and mix with sugar OR liquid stevia, and with the cinnamon, if using. Add water (or juice), and if using, food colouring and almond extract. Stir constantly over medium heat until mixture gets quite thick and begins to bubble. Add lemon juice, cook one additional minute. Fold in the cherries carefully all at once just until evenly mixed.
Fill piping hot mixture into hot jars.
Ladle into 1/2 litre (1 US pint / 16 oz) jars or 1 litre (1 US quart / 32 oz) jars.
Leave 3 cm (1 1/4 inch) headspace.
Debubble well, adjust headspace.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process either size jar for 30 minutes; increase time as needed for your altitude.