I highly recommend you start by chilling a mixing bowl and the beaters from your electric mixer in the refrigerator for about 15 minutes. This helps the cream whip up faster and stay cold, though it's not absolutely necessary.
Pour the chilled heavy cream into the chilled mixing bowl, then start beating the cream on medium speed until it begins to thicken.
Start beating the cream on medium speed until it begins to thicken.
Gradually sift the powdered sugar, matcha powder, and a pinch of salt into the cream while continuing to beat.
Increase the speed to high and beat until stiff peaks form. Be careful not to over whip, or the cream will become grainy.
Use immediately, or store in the refrigerator for up to 24 hours. Give it a quick whisk before serving if needed.