Preheat oven to 350 degrees F. Put mini muffin liners in muffin tin.

In a bowl sift together flour, matcha powder, baking soda and salt.

In a different bowl beat together sugar, eggs, oil and 1 teaspoon vanilla.

Add half of the dry mixture stirring just until incorporated then add half the sour cream, stirring lightly. Add the rest of the dry mixture and then the sour cream, stirring until incorporated.

Fill mini muffin liners 2/3 of the way full. Bake for 10-12 minutes (checking that a toothpick comes out clean). Leave in muffin tin for 10 minutes and then remove. Cool completely before frosting.

For the frosting sift together confectioners sugar, and matcha powder.

In a separate bowl beat together cream cheese, 1/2 teaspoon vanilla and butter for 4-5 minutes. On low speed slowly add the dry mixture then increase speed to medium and beat for another 4-5 minutes.

Frost using a piping bag.