01 - Combine cherry preserves, water, and lemon juice in a small saucepan. Heat over low heat, stirring constantly until smooth and syrupy, approximately 2 minutes. Strain through a fine-mesh sieve if a completely smooth texture is preferred.
02 - Prepare one shot of fresh espresso using an espresso machine or brew 1/4 cup of strong, concentrated coffee using a coffee maker or French press.
03 - Heat the milk in a small saucepan until steaming hot, then use a milk frother or steam wand to create a velvety foam. Alternatively, shake vigorously in a sealed jar and microwave until hot.
04 - Add the prepared cherry syrup and vanilla extract to a large mug. Pour the hot espresso over the syrup mixture and stir thoroughly to incorporate all flavors.
05 - Pour the steamed milk over the espresso-cherry base, using a spoon to hold back the foam. Gently spoon the reserved foam on top of the beverage.
06 - Top with whipped cream if desired, drizzle with additional cherry syrup, and place a fresh or maraschino cherry on top. Serve immediately while hot.