01 - Preheat oven to 350°F. Grease and flour three 8-inch cake pans, lining bottoms with parchment paper.
02 - Whisk together flour, baking powder, and salt in a medium bowl until thoroughly combined.
03 - Beat butter and sugar in a large mixing bowl until light and fluffy, approximately 3-4 minutes. Add eggs one at a time, then incorporate vanilla extract.
04 - Alternate adding flour mixture and milk to creamed batter in three additions, beginning and ending with flour. Mix until just combined.
05 - Divide batter evenly among prepared pans. Bake for 28-32 minutes until a toothpick inserted in center comes out clean. Cool in pans for 10 minutes, then transfer to wire racks to cool completely.
06 - Combine sugar and water in a heavy saucepan over medium heat, swirling until sugar dissolves. Increase heat to medium-high and cook until golden amber, 7-10 minutes. Remove from heat and whisk in butter, cream, and salt. Cool to room temperature.
07 - Beat butter until creamy. Gradually add powdered sugar, then incorporate caramel sauce, vanilla, and salt. Beat until light and fluffy for 2-3 minutes.
08 - Place first cake layer on serving platter and spread with generous caramel frosting layer. Repeat with remaining layers. Frost top and sides completely. Drizzle extra caramel sauce over top for glossy finish.
09 - Refrigerate assembled cake for at least 30 minutes before serving to achieve cleaner slices.