Preheat oven to 350 degrees F.
In a large bowl, mix together the rice flour, baking powder, and matcha powder. Make sure to sift the matcha powder to avoid clumps.
In a separate medium bowl, whisk together the butter, vanilla extract, and sugar. Add in the eggs and whisk until combined. Finally, add in the coconut milk and whisk until combined.
Pour the wet ingredients into the large bowl with the dry ingredients. Use a spatula to combine until you get a thick dough.
Spoon the dough into a pastry bag or use a ziplock bag to pipe the dough into a donut pan. I used a donut pan with donut molds that are 3 3/4 inch in diameter.
Grease the donut pan. Pipe your batter into the donut molds.
Bake for about 7-9 minutes.
Make the glaze. Add all the ingredients for the glaze into a small bowl and whisk together. Again, make sure to sift the matcha powder to avoid clumps.
Once the donuts are out of the oven, cool for 20 minutes.
Dip donuts into the glaze and put them on a cooling rack to dry. It should take about 20 minutes for the glaze to fully dry.