Prep time. Pre-heat your oven to 180C and take out your butter to bring it up to room temperature. In a bowl, mix together your sugar and baking powder, and grease your baking pan.
Let’s mix. Cream together the butter and sugar, until smooth and lump free. Next, add in the egg little by little. Finally stir in the flour a third at a time, before stirring in the milk. You don’t need to pour in all the milk if it’s starting to get too runny.
Separate your batter in half and stir in the matcha to one half. When it’s mixed through and nicely green, gently stir in the green batter to the plain batter. Don’t go too crazy or you won’t get the nice marbling effect, just enough to swirl it all together.
Pour into your baking pan and cook for around 40 minutes. Cooking times will vary depending on your oven, so it’s worth checking with a skewer or knife after about 20-30 mins. When the skewer comes out clean, your cake is done.