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 granulated sugar in a large mixing bowl until light and fluffy, approximately 3-4 minutes. Add eggs one at a time, incorporating fully before each addition. Stir in vanilla extract.
04 - Alternate adding flour mixture and milk to creamed batter in three additions, beginning and ending with flour mixture. Mix until just combined, taking care not to overmix.
05 - Divide batter evenly among prepared pans. Bake for 28-32 minutes until a toothpick inserted in the center emerges 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. Swirl pan gently until sugar dissolves, avoiding stirring. Increase heat to medium-high and cook until mixture reaches golden amber color, 7-10 minutes. Remove from heat and carefully whisk in butter, followed by cream and salt. Cool to room temperature.
07 - Beat butter until creamy. Gradually incorporate powdered sugar, then add caramel sauce, vanilla extract, and salt. Continue beating until light and fluffy, approximately 2-3 minutes.
08 - Place first cake layer on serving platter. Spread generous layer of caramel frosting over surface. Repeat with remaining layers. Apply frosting to top and sides of assembled cake. Drizzle additional caramel sauce over top for glossy finish.
09 - Refrigerate assembled cake for minimum 30 minutes before serving to ensure clean slicing.