To make the candied sage leaves, place ¼ cup sugar and water in a small saucepan. Whisk to combine and warm over medium-low heat.
Stir until the sugar dissolves, about 3 to 4 minutes.
Place the sage leaves on a sheet of wax paper, evenly spaced.
Brush both sides of the sage leaves with the simple syrup.
Generously sprinkle the brushed sage with the remaining granulated sugar and transfer to a wire rack to dry, about 2 hours.
To make the brown sugar syrup, place the orange juice, minced ginger, star anise, cardamom pods, and cinnamon sticks in another small saucepan. Bring the mixture to a simmer over medium heat and cook until the orange juice has reduced by half, about 10 minutes.
Remove the baking spices from the saucepan using a slotted spoon and discard.
Add the brown sugar to the saucepan and whisk to combine. Continue to simmer until the sugar has dissolved, about 2 minutes more.
Strain the mixture through a fine mesh sieve to catch any missed baking spices. Set the syrup aside to cool at room temperature.
To make the cocktails, fill glasses (rocks or collins) with ice and pour 2 ounces of whiskey into each glass.
Pour 1 ounce of brown sugar syrup into each glass and stir.
Top the glasses with ginger beer.
Garnish the cocktails with candied sage leaves and orange peels before serving.