Preheat oven to 350°F (175°C).
Grease and flour a 9-inch cake pan or line with parchment paper.
In a bowl, whisk together flour, baking powder, and salt. Set aside.
Using an electric mixer, beat butter and sugar until light and fluffy (~3 mins).
Beat in eggs one at a time, then add vanilla extract.
Mix in ½ of the flour mixture, then ½ of the milk. Repeat until just combined (do not overmix).
Pour batter into the pan and smooth the top.
Bake for 25-30 mins or until a toothpick comes out clean.
Let cool in the pan for 10 mins, then transfer to a wire rack.
Frost or dust with powdered sugar (optional).
