Make the espresso. Stir the instant espresso powder into the hot water and set aside.
Prepare the milk mixture. In a glass measuring cup, combine the milk, cinnamon, brown sugar, vanilla, and nutmeg, then whisk until combined. Microwave for 1 minute and 30 seconds, or until the milk starts to froth. Watch it closely.
Continue to froth the milk. Remove the milk mixture from the microwave and stir. Return it to the microwave for an additional 30 seconds, or until the milk starts to froth again.
Combine the coffee and milk. Remove the milk mixture from the oven and, while stirring the espresso, slowly pour it into the coffee. Continue to stir until well combined.
Serve. Top with whipped cream and garnish with cinnamon, then serve.
Notes
Brewed espresso: For this latte, you want a strong cup of coffee like espresso to balance the creaminess and sweetness. If you're not using instant espresso as the recipe calls for and are using coffee beans instead, use high-quality beans to brew the espresso. The espresso is the backbone of your latte, so you'll want it to be top-notch. You'll need 6 ounces.
Don't skip the heating of the milk. Heat it slowly, either in the microwave or on the stovetop, stirring frequently to prevent burning. If you have one, a milk frother works wonders.
Adjust to your liking: One benefit of making a copycat recipe at home is that you can adjust the sweetness and flavorings to your preference. You can also make your latte without dairy by using almond milk, soy milk, or oat milk.
Storage: If you make a larger batch of cinnamon dolce syrup, store it in the fridge.