If you have a clear ice maker, follow the maker's instructions to make the ice at least a day in advance.
Let the ice sit at room temperature to warm up ("temper") while you make the drink. If it's too cold, it may crack when you pour the drink in the glass.
Cocktail
Add the pumpkin spice syrup, rye whiskey, and both bitters to a cocktail mixing glass.
Give the ingredients a quick stir to incorporate the syrup. Then, fill the mixing glass with ice and stir for about 30 seconds.
Add fresh ice (or an ice sphere if you have it) into your serving glass.
Strain the drink into the glass.
Add the cinnamon stick and dried orange slice garnishes, and serve!
If you want to make a big batch of these cocktails, just use the calculator above! Scroll up to where it says "Servings - 1 cocktail" and hover your mouse or tap on the number 1. A slider will pop up. Just slide it to the right to increase the number of servings.
When you're making a big batch, add in ½ ounce of water per cocktail. This way, you can skip stirring with ice and just serve 3 ounces of the mixed batch per drink.