In a small saucepan, combine the dark brown sugar, white granulated sugar, and molasses with 3 tablespoons (45 ml) of water. Warm over low heat, stirring constantly until the sugars dissolve and the mixture is smooth but not boiling (about 2–3 minutes). Remove from heat.

Add aromatic extracts & juices

Stir the vanilla extract, almond extract, maraschino cherry juice, optional cherry concentrate (if using), cola syrup or cola extract (if using), lemon juice, orange juice, ground cinnamon and ground nutmeg into the warm syrup until fully incorporated. Taste carefully: the syrup should read sweet with a noticeable cherry/vanilla/almond aroma and a faint spice note. If it's too strong, add a teaspoon of hot water; if too weak, add a little more cherry juice or a pinch more cinnamon.

Cool the syrup

Let the flavored syrup cool to room temperature (about 10–15 minutes). For faster cooling, transfer to a small bowl and place in the refrigerator for 5–7 minutes. The syrup will thicken slightly as it cools.

Assemble the soda

Fill a tall glass with about 1 cup of cold ice. Pour the cooled syrup over the ice (use approximately 3 tablespoons of syrup per 8 ounces / 1 cup of finished soda; adjust to taste). Slowly pour 1 cup (240 ml) carbonated water over the syrup so it mixes gently and retains fizz. Stir once gently with a long spoon to incorporate the syrup into the soda without losing too much carbonation.

Garnish and serve

Top with the maraschino cherries and serve immediately. Taste and adjust: add more carbonated water to lighten, or more syrup (½–1 tsp at a time) for sweetness and stronger flavor. This recipe scales: multiply syrup quantities proportionally if making a larger pitcher; keep syrup refrigerated up to 1 week.