In a small bowl or measuring cup, combine the prune juice, cherry syrup (or grenadine), almond extract, vanilla extract, liquid caramel (or caramel syrup), and molasses (or dissolved dark brown sugar). Stir thoroughly until uniform. This concentrated blend provides the signature Dr Pepper notes.

Taste the blend. It should be noticeably flavorful but not overly sweet — the cola base will dilute and balance it. Adjust by adding up to 1/4 tsp additional cherry syrup for more cherry note, or 1/4 tsp additional vanilla if desired.

Assemble Soda

Fill a tall glass with the ice cubes.

Pour the chilled carbonated water into a large measuring cup. Add the 1/4 cup cola syrup (or cola-flavored simple syrup) and the 1 tablespoon chilled simple syrup. Stir gently to incorporate — do not stir vigorously to avoid flattening the carbonation.

Add the prepared signature flavor blend to the cola mixture. Add the fresh lime juice. Stir gently once or twice to distribute the flavors.

Taste the soda and adjust sweetness or acidity as needed: add up to 1/2 tablespoon extra simple syrup to sweeten, or another 1/4 tsp lime juice to brighten.

Finish & Serve

Pour the flavored cola carefully over the ice in the prepared glass to preserve carbonation.

Garnish with a maraschino or fresh cherry and an optional lime wedge. Serve immediately while fizzy.