Preheat the oven to 350°F (180°C).
Butter or spray an 8x4-inch loaf pan.
Line with a strip of parchment paper, covering the pan's bottom and two short sides. The two long sides will remain unlined but greased. This will help remove the cake from the pan after it’s baked.
In a large bowl, beat butter and sugar until creamy, about 2 minutes.
Add eggs one at a time, beating well after each addition.
Sift together flour, baking powder, and salt.
Add to the egg mixture in three additions, alternating with milk and vanilla in two additions.
Pour into prepared pan and bake for about 45 minutes or until a tester comes out clean. It will become shiny on top.
Transfer to a cooling rack, poke the surface of the loaf with a wooden brochette skewer, cake thermometer, or something similar, and pour ½ of the honey syrup on top of the hot cake.
Brush the remaining half so that the top surface is well covered.
Let cool before removing from the pan. If the sides are stuck from the syrup, run a smooth-bladed knife around the edges so that it unmolds without breaking.