Step 1

Place chocolate and vanilla in a medium heat proof mixing bowl and set aside.

Step 2

Heat cream in a small saucepan over medium-high heat, swirling occasionally until steaming hot and simmering along the edges. Pour over the chocolate and whisk until all the chocolate is melted, about 3 minutes. (See tip.) Whisk in ½ teaspoon matcha powder. Refrigerate until firm, 2 to 4 hours (or overnight.)

Step 3

Scoop 1 tablespoon portions of the chocolate mixture and roll into balls. Roll the balls in the remaining matcha or pistachios. Refrigerate until serving.