Step 1

Add water and brown sugar to a small saucepan and mix.

Step 2

Turn to high heat and add cinnamon stick to the saucepan.

Step 3

Bring the mixture to a boil and then turn the heat to low.

Step 4

Let the simple syrup simmer for 5-10 minutes.

Step 5

Remove from heat and let cool.

Step 6

Add 1/2 cup of ice to a mason jar and 1/2 cup of ice to a separate glass.

Step 7

Next, add espresso and brown sugar simple syrup to the mason jar with the ice. Cover and shake.

Step 8

Pour the mixture over the ice in the glass.

Step 9

Empty the mason jar and pour the oat milk into the jar.

Step 10

Use a frother to froth the oat milk until froth forms.

Step 11

Pour the oat milk froth over the espresso, mix, and enjoy.