Preheat your oven to 325°F (165°C). Thoroughly grease and flour a 10-inch tube pan or bundt pan, ensuring every crevice is coated. For extra insurance against sticking, consider lining the bottom with parchment paper.
In a large mixing bowl, beat the softened butter until creamy and noticeably lighter in color (about 2 minutes). Gradually add the sugar, about ½ cup at a time, beating for 30 seconds between additions. Continue beating for 5-7 minutes total until the mixture is fluffy and pale yellow.
Add eggs one at a time, beating for approximately 45 seconds after each addition. Stop and scrape down the bowl frequently. The mixture may look slightly curdled—this is perfectly normal and will smooth out once you add the flour.
Combine the sifted flour, salt, and baking powder in a medium bowl. In a measuring cup, combine milk and vanilla extract. Add the flour mixture to the butter mixture in three parts, alternating with the milk mixture (begin and end with flour). Mix on low speed just until incorporated after each addition.
Pour the batter into your prepared pan, gently tap on the counter to release air bubbles, and smooth the top with a spatula. Bake at 325°F for 70-80 minutes, or until a wooden skewer inserted in the center comes out with a few moist crumbs (not wet batter).
Allow the cake to cool in the pan for exactly 15 minutes (set a timer!). Then invert onto a cooling rack and gently remove the pan. Let cool completely for at least 2 hours before slicing for the perfect texture.