Preheat your oven to 350°F and generously grease a 9x5-inch loaf pan with butter or non-stick cooking spray, ensuring all sides are covered.
In a medium bowl, whisk together the flour, baking powder, and salt until well combined to ensure your cake has an even, light texture.
In a separate large bowl, use an electric mixer on medium speed to cream together the softened butter and sugar for 2-3 minutes until the mixture is pale yellow, fluffy, and light.
Beat the eggs into the butter mixture one at a time, fully incorporating each one before adding the next, then mix in the vanilla extract.
Alternately add the flour mixture and milk to the wet ingredients in three parts, starting and ending with the flour, mixing on low speed just until the batter is smooth with no dry streaks.
Pour the batter into the prepared loaf pan and use a spatula to spread it into an even layer, then bake for 50-60 minutes until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan on a wire rack for 15 minutes before carefully turning it out onto the rack to cool completely for at least 1 hour before slicing.