Begin by filling a medium-sized saucepan with 4 cups of water. Place the saucepan over medium-high heat and bring the water to a rolling boil.

While waiting for the water to boil, zest one large orange and set it aside for later use.

Once the water is boiling, remove it from heat and add tea bags, cinnamon sticks, reserved orange zest, and optional star anise. Cover and steep for 5-8 minutes.

Cut the zested orange in half and juice it, straining to remove seeds or pulp.

After steeping, strain out tea bags and spices, then stir in orange juice and sweetener to taste.

Allow the infused tea to cool, then refrigerate for at least 30 minutes.

To serve, fill glasses with ice and pour in the chilled tea. Garnish with fresh orange slices.