Place 2 tablespoon of black sesame paste into a serving glass.
In a separate jar, add in 1 teaspoon hojicha powder and ¼ C hot water. Whisk with an electric whisk or chasen until frothy. Pour on top of the black sesame paste.
In another jar, froth up the warmed oat milk and carefully pour it over top of the hojicha and black sesame. You can omit frothing the oat milk if you prefer.
If you want to make it iced, add some ice cubes to the glass before pouring in the chilled oat milk.