Using a hand mixer, in a medium sized mixing bowl cream the butter and powdered sugar together until smooth and the mixture becomes a pale-yellow color. This should take about 5 minutes.
Beat through the egg for 1 to 2 minutes.
Add the vanilla extract, corn starch, salt, and matcha powder to the butter and sugar. Mix until well combined.
Add the chopped chocolate chips and almonds and mix through the dough.
Add the rice flour gradually and mix in well.
Form the dough into a ball. Weigh out 20 grams (0.71 ounces) pieces of dough and shape into balls. Place on a baking tray lined with parchment paper. Gently flatten the balls with the back of a fork or your fingers.
Once you have divided your dough, place the baking tray in the fridge for at least 1 hour.
Making the Cookies
Preheat oven to 180°C (356°F).
Bake cookies for 10 to 15 minutes or until the edges of the cookies just start to change color.
Remove from oven once cooked and allow to cool completely on the tray.
Transfer to an airtight container or cookie jar once cool.