01 - Preheat oven to 350°F. Grease and flour three 8-inch cake pans, then line bottoms with parchment paper.
02 - Whisk together flour, baking powder, and salt in a medium bowl until evenly distributed.
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, then mix in vanilla extract.
04 - Alternate adding flour mixture and milk to creamed batter in three additions, beginning and ending with dry ingredients. 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 release onto wire racks to cool completely.
06 - Combine sugar and water in a heavy saucepan over medium heat, swirling pan gently until sugar dissolves. 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 heavy 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 - Position first cake layer on serving platter. Spread a 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 finished cake for at least 30 minutes to set frosting, ensuring cleaner slices when serving.