For the matcha glaze, wisk all ingredients together and place in a small bowl or jar.
Preheat oven to 350°F and place the rack in the middle position. Grease a loaf pan 8x4 inches and set aside.
Stir mashed avocado and lemon juice together in a small bowl and set aside. (For a more uniform color, you can use a hand blender)
Mix matcha powder and water until there are no lumps.
Combine the baking soda and sour cream, set aside.
In another bowl, mix the flour and salt together and set aside.
With the aid of a hand blender or stand mixer, beat the butter and sugar over med speed until well blended and fluffy. Add the eggs one at a time mixing well in between. Add the vanilla, matcha mixture and the sour cream.
In three stages, alternate between the avocado puree and the dry ingredients until the mixture is well blended.
Pour batter in prepared pan and bake for 40 minutes.
Cover in aluminum paper and continue cooking for another 10-15 minutes until a wooden skewer comes out clean when placed in the center of the bread.