Preheat oven to 350 degrees F (175 degrees C). Grease a tube pan with some butter and dust lightly with flour.
Mix flour, baking powder, and salt together in a bowl.
Combine sugar and butter in a large bowl; beat with an electric mixer until creamy. Add eggs one at a time, beating well between each addition. Beat in flour mixture alternately with milk. Mix in vanilla extract. Pour batter into the prepared tube pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 1 hour to 1 hour 30 minutes. Cool in the pan for 5 minutes. Invert onto a wire rack and let cool completely, about 30 minutes.