Preheat the oven to 350°F (175°C).

Grease your loaf pan with butter or cooking spray.

In a mixing bowl, cream together the softened butter and sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition.

In another bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry mixture to the butter mixture, alternating with milk, starting and ending with flour.

Stir in the vanilla extract until combined.

Pour the batter into the prepared loaf pan and smooth the top.

Bake in the preheated oven for about 60 minutes, or until a toothpick inserted in the center comes out clean.

Let the cake cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.