• In a large, heat-safe glass bowl, combine sugar and egg whites.
Set bowl over a pan of simmering water, and whisk constantly
until mixture registers 140° on an instant-read thermometer.
• Remove bowl from heat, and using an electric mixer at medium-high
speed, beat mixture until fluffy and cool, about 10 minutes.
• Reduce mixer speed to medium-low, and add butter 1 tablespoon
at a time, mixing well after each addition. Add matcha
and vanilla extract, and beat well to combine. Use immediately,
or place in an airtight container and refrigerate for up to 3 days
or freeze for up to 1 month. To prepare refrigerated or frozen
frosting, bring to room temperature, and beat with an electric
mixer at low speed until smooth, approximately 3 minutes.

 
*For testing purposes, we used AOI Tea Company’s Chef ’s Choice Matcha,
which can be purchased ataoitea.com.