Step 1: Preheat your oven to 350°F (175°C).
Step 2: Grease your loaf pan with butter or non-stick spray, and lightly dust it with flour.
Step 3: In a stand mixer, combine the unsalted butter and granulated sugar. Beat on medium speed until light and fluffy, about 4-5 minutes.
Step 4: Add the eggs one at a time, mixing well after each addition.
Step 5: Stir in the lemon zest.
Step 6: In a separate bowl, whisk together the all-purpose flour, salt, and baking powder.
Step 7: With the mixer on low speed, alternate adding the dry ingredients and the whole milk to the batter, starting and ending with the flour mixture.
Step 8: Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Step 9: Bake for 60-70 minutes, or until a toothpick inserted into the center comes out clean.
Step 10: Allow the cake to cool in the pan for about 10 minutes before transferring it to a cooling rack. Let it cool completely before slicing.
