Preheat oven to 350 degrees F. Line 12-well muffin pan with paper liners.

In large bowl, whisk together eggs, oil, water and vanilla. Add cake mix and whisk until well combined.

Spoon batter into muffin cups, filling each about 2/3 full. Bake 15-20 minutes or until toothpick comes out clean. Cool completely before frosting.

In bowl, combine frosting and matcha, mixing until green color uniform throughout.

Using spatula or piping bag, frost cupcakes.

Store in fridge or freezer.