Gather all the ingredients. Make sure the butter, eggs, and milk are all at room temperature. It’s important! Center a rack in the oven and preheat the oven to 350ºF (180ºC). For a convection oven, reduce cooking temperature by 25ºF (15ºC).
I use the leftover butter on the butter wrapping paper to grease the pan (8.5 x 4.5 x 2.75 inches). Then place the parchment paper inside the pan (paper will stick to the butter).
Put the softened butter in a large bowl and beat it with medium speed until it is light and fluffy (pale color) and lots of little tails foam around the beaters, about 1-2 minutes. Tip: This process adds air to the mixture, and it is crucial for the light and delicate texture of the pound cake.
Add the sugar to the whipped butter. Cream the butter and sugar thoroughly with medium speed (not high speed), about 5 minutes, until it is light and fluffy. The color is pale and sugar is completely dissolved. Tip: The sharp sugar grains cut through the butter and create the tiny air pockets that aerate the batter and cause leavening. This process is very important for the light and delicate texture of the pound cake.
Crack the eggs in a small bowl and whisk well.
IMPORTANT: To achieve a smooth mixture (not a curdled mixture), add in a very small amount (1 Tbsp) of the whisked egg in the mixture and beat well after each addition. Tip: The eggs contain water and the yolks and the butter are fats. Remember, oil and water will not mix without an emulsifier (in this case, the yolks), which suspends fat molecules in water making a smooth mixture.
If there is a slightly curdled appearance to the batter after adding the eggs, don’t worry. The emulsification is usually complete enough that the batter will become smooth with the addition of flour. The flour helps absorb some of the excess water.
Add the dry ingredients in 3 additions. In a fine-mesh strainer/sifter, add a mixture of 200 g (1 ⅔ cup) cake flour, 1 tsp baking powder, and ¼ tsp salt and sift a third of it over the egg mixture. Switch to a silicone spatula (or with mixer on the lowest speed), and mix the mixture by hand so you can scrape to the bottom of the bowl to get any little pockets of flour.
Now add another third of the dry ingredients and mix.
Stir in the last third addition. Mix only until the batter is smooth. Tip: Even though we are using a low protein cake flour, excess mixing will develop the gluten and the cake will rise nicely in the oven, then sink as soon as you pull it out. And the sinking cake is what makes a tougher cake and dense, moist, gluey streaks.
Heat 60 ml (¼ cup) milk in a microwave or saucepan until warm (roughly body temperature) and gradually add the milk to 20 g (3 Tbsp) matcha in the bowl, 1 Tbsp of milk at a time. Whisk well till combined. Tip: Warm liquid is easier to blend matcha.
Take ⅓ of the batter and add to the bowl with matcha.
Fold in just until the batter is smooth and homogenous. Do not overmix.
Add 6-8 dollops of matcha batter into the original batter. Then fold the entire batter from the bottom of the bowl THREE (3) times.
Pour the batter into the pan without mixing the batter, keeping the swirl effect. Tap the cake pan on the countertop once to release the trapped air.
Using the offset spatula, smooth out the surface without mixing too much.
Put the cake pan in the oven and lower the oven temperature to 340ºF (170ºC) oven for 50 to 60 minutes.
After 15 minutes, open the oven and quickly score the top of the cake with a sharp knife (Read the blog post why we do this). Continue to bake.
The cake is done when a wooden skewer inserted in the center of the cake comes out clean.
Remove from the oven and allow the cake to rest in the pan for 15 minutes on a wire rack before taking the cake out of the pan to cool completely. Enjoy!
You can keep the leftovers in an airtight container (or wrap in plastic) and store it in the refrigerator for up to 3 days and in the freezer for up to 3 months.