Measure and prepare heavy cream or oat milk, sweetener, matcha powder, and ice water along with all equipment.

Sift matcha powder into the frother pitcher or a small bowl to remove any clumps.

Add heavy cream and sweetener to the sifted matcha and whisk gently until incorporated.

Froth the mixture using an electric or handheld frother for 30 to 60 seconds until soft peaks form.

Meanwhile, prepare your base drink by pouring cold milk or iced coffee over ice in a tall glass, leaving 1 inch of space at the top.

If the foam is too bubbly, run a whisk through it a few times to create a smoother consistency.

Use a spoon to gently layer the cold foam on top of your prepared drink.

Dust a pinch of matcha powder over the foam if desired and serve immediately.