01 - Preheat oven to 350°F. Grease and flour a 9x5-inch loaf pan or bundt pan.
02 - In a medium bowl, whisk together all-purpose flour, baking powder, and salt. Set aside.
03 - In a large bowl, beat the softened butter and granulated sugar with a mixer until pale and fluffy, approximately 3 to 4 minutes.
04 - Add eggs one at a time, ensuring each is fully incorporated before adding the next.
05 - Mix in pure vanilla extract and scraped vanilla bean seeds, if using, until evenly distributed.
06 - With mixer on low speed, alternately add flour mixture and milk in three batches, starting and ending with flour. Mix just until combined; do not overmix.
07 - Transfer the batter to the prepared pan and level the surface with a spatula.
08 - Bake for 50 to 60 minutes, or until a toothpick inserted in the center emerges clean.
09 - Allow cake to cool in pan for 10 minutes, then turn onto a wire rack to cool thoroughly before serving.