In a large bowl, add in the mochiko flour, cornstarch, baking powder, and kosher salt. Sift in the matcha powder to ensure there are no lumps then whisk until the ingredients are evenly distributed.
In a separate bowl, beat the eggs together. Then mix in the granulated sugar, whole milk, and vanilla extract. Pour the bowl of wet ingredients into the dry and whisk until a smooth batter forms.
Preheat your waffle iron according to the manufacturers directions. Spray the inside with cooking spray and add in a portion of the waffle batter. For a 7-inch round Belgian waffle maker, I used ¾ cup of batter to make 1 waffle and cooked it for about 1½ - 2 minutes on each side until lightly browned. Try to gauge the best measurements and cooking time based on the size and temperature controls of your waffle maker. Remove the waffle from the iron and place it on a cooling rack while you prepare the remaining waffles.
Allow the waffles to cool for 3 minutes to allow the mochi texture to settle. These waffles are best served warm and you can top them however you like! I topped mine with a dusting of powdered sugar, whipped cream, strawberries, and maple syrup. Enjoy!