1/2 cup (113 grams) unsalted butter, room temperature 2/3 cup (130 grams) granulated white sugar 3 large eggs 1 teaspoon pure vanilla extract Zest of 1 large lemon (optional---เลยไม่ใส่มันสะเลย) 1 1/2 cups (210 grams) all purpose flour---เราใช้แป้งเค้กแทนนะ 1 1/2 teaspoons baking powder 1/4 teaspoon salt 1/4 cup (60 ml) milk