Combine 1 cup granulated sugar and 1 cup water in a small saucepan. Add the orange zest. Bring to a gentle simmer over medium heat, stirring until the sugar dissolves. Reduce heat and simmer 4–5 minutes to slightly thicken and infuse the orange flavor.

Remove from heat, stir in 2 tablespoons fresh orange juice. Let cool to room temperature with the zest in the syrup for at least 15 minutes for stronger flavor.

Strain the syrup through a fine mesh sieve to remove zest solids. Transfer to a clean jar. Syrup keeps refrigerated up to 2 weeks.

Chocolate Base

In a small cup, whisk 2 tablespoons unsweetened cocoa powder with 2 tablespoons hot water until smooth and lump-free to make a chocolate paste.

Add 1 teaspoon simple syrup or sugar to sweeten and whisk until incorporated. Taste and adjust sweetness as desired. Set aside.

Assemble Drink (Hot or Iced)

For Hot Orange Mocha

Heat 10 oz oat milk gently on the stove or with a steam wand to about 150°F (65°C). Froth slightly if desired. In a 12–16 oz cup combine 2 shots of hot espresso, 1.5 tablespoons housemade orange syrup, and the prepared chocolate base (about 2 tablespoons). Stir thoroughly to combine, then pour the steamed oat milk over the mixture. Stir gently. Garnish with an orange twist and a light dusting of grated dark chocolate or cocoa powder.

For Iced Orange Mocha

Fill a tall glass with about 1 cup ice. In a separate small pitcher combine 2 shots of cooled espresso, 1.5 tablespoons housemade orange syrup, and the prepared chocolate base (about 2 tablespoons). Stir until chocolate base is fully dissolved. Pour the mixture over the ice, then add 10 oz cold oat milk. Stir to combine. Garnish with an orange twist and optional grated chocolate.

Adjust sweetness and orange intensity by adding more or less housemade orange syrup or chocolate base to taste.