Directions

1. Gather all the ingredients. It‘s important that the butter, eggs, and milk are all at room temperature. Center a rack in the oven and turn on the oven to 350ºF.
   
2. Use the residual butter on the butter wrapper to grease the pan (8½ x 4½ x 2¾ inches). Then, place the parchment paper inside the pan. Use a light-colored pan for this recipe.
   
3. Put the butter in the bowl of an electric mixer with beater attachment. Beat it on medium speed until it is light and fluffy, about 1–2 minutes. The butter will be pale in color and have lots of little tails forming around the beaters.
   
4. Add sugar to the whipped butter. Cream the butter and sugar thoroughly on medium speed, about 5 minutes, until it is light and fluffy. The color is pale and the sugar is completely dissolved.
   
5. Crack 4 large eggs in a small bowl and whisk well. Add the beaten eggs, 1 tablespoon at a time, to the butter mixture and beat well after each addition. Repeat until all the egg is incorporated.
   
6. Put cake flour, baking powder, and salt in a fine-mesh sieve and sift. Place one-third of these dry ingredients into the bowl of the egg mixture. Switch to a silicone spatula and fold the mixture by hand so you can scrape the bottom of the bowl to get any dry pockets of flour. Now, add another one-third of the dry ingredients and fold again. Finally, stir in the remaining dry ingredients. Fold it just until the batter is smooth.
   
7. Heat milk in a microwave until warm (roughly body temperature). Gradually add the milk, 1 tablespoon at a time, to matcha in a medium bowl. Whisk well until combined. Add one-third of the batter to the bowl with the matcha paste. Use a silicone spatula to fold the batter into the matcha paste just until it's smooth and homogenous. Do not overmix.
   
8. Now, combine the green and yellow batters to create a marbled pattern. Add the matcha batter to the original yellow batter in 6–8 separate dollops scattered around the bowl. To swirl the two batters, use a silicone spatula to scoop the batter from the bottom of the bowl and fold it onto itself while rotating the bowl a quarter turn. Repeat this two more times only.
   
9. Pour the batter into the pan without mixing the batter, keeping the swirl effect. Tap the cake pan on the countertop once to release an air pockets. Using an offset spatula, smooth out the surface of the batter without mixing too much. Put the cake pan in the oven. Lower the oven temperature to 340ºF and bake for 50–60 minutes. After 15 minutes of baking, open the oven and quickly score the top of the cake with a sharp knife. Continue to bake, monitoring the oven to maintain a temperature of 340ºF.
   
10. 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. Then, take the cake out of the pan to cool completely. Once it’s cool, you can slice and serve the Matcha Marble Pound Cake, if you wish. However, I strongly recommend serving it the next day (and up to 3 days after baking). This gives the butter time to oxidize and blend into the cake, resulting in a moister texture and allowing the flavors to meld and improve for a deeper matcha taste. Tightly wrap the cake and keep it in an airtight container at room temperature until ready to serve.