Preheat oven to 350º and prepare three 6-inch or two 8-inch cake pans by spraying the sides with baking spray and placing a pre-cut wax or parchment paper circle to fit the bottom.
Whisk together sifted cake flour, Matcha powder, baking powder, baking soda, and salt. Set aside.
Cream butter on med-high for one minute. Scrape down bowl and paddle. Add sugar and beat on high for 2-3 minutes, until light and fluffy, scraping down bowl and paddle as needed.
Turn the mixer down to low and add the eggs one by one. Scrape down bowl, turn the mixer on med-high and beat for about 2 minutes. Add the sour cream and vanilla, continue beating for 1 minute.
Add all of the dry ingredients at once with the mixer on low speed until just combined, then add the milk all at once with the mixer still on low. Scrape down the bowl and paddle and mix on low until it all just comes together. You might need to hand whisk at the end to get rid of some lumps, but be careful not to overmix.
Fill prepared cake pans ⅔ full and bake for 30-35 minutes or until a toothpick inserted comes out clean.