Rinse and dry the cherries, then pit and halve them (about 10 minutes).

Sterilize a quart-sized glass jar by washing with hot soapy water, rinsing thoroughly, and air drying completely (10 minutes).

Layer half of the cherries in the jar, sprinkle half of the sugar over them, add the remaining cherries, and top with the rest of the sugar (5 minutes).

Pour the vodka over the cherry and sugar mixture until submerged, then stir gently with a wooden spoon to combine (2 minutes).

Seal the jar tightly and store in a cool, dark place for 3 to 4 weeks without disturbance.

Every 3 to 4 days, shake the jar gently for 10 seconds to redistribute the sugar and fruit.

After 3 weeks, taste a small sample; the liqueur should be deep red with balanced sweetness and no harsh alcohol burn.

Strain the liquid through a cheesecloth-lined colander into a bowl, then filter through a coffee filter into clean bottles for clarity (about 10 minutes).

Seal and label the bottles with the date, then let the liqueur age an additional week or two for optimal flavor before serving.