Step 1: Preheat your oven to 325°F (160°C). Grease and flour a 10-12 cup Bundt pan or a 9x13 inch baking pan. Tap out any excess flour.
Step 2: In a large bowl, cream together the softened butter and 2 cups granulated sugar with an electric mixer until light and fluffy (about 3-5 minutes).
Step 3: Add the eggs one at a time, beating well after each addition until fully incorporated. Scrape down the sides of the bowl as needed. Stir in 1 teaspoon vanilla extract.
Step 4: In a separate bowl, whisk together the all-purpose flour, baking powder, and 1/2 teaspoon salt.
Step 5: Gradually add the dry ingredients to the wet ingredients in three additions, alternating with the milk. Begin and end with the dry ingredients. Mix on low speed until just combined and no streaks of flour remain. Do not overmix.
Step 6: Pour the batter evenly into the prepared pan. Bake for 70-80 minutes, or until a wooden skewer inserted into the center comes out clean. If using a 9x13 pan, baking time may be slightly shorter (50-60 minutes).
Step 7: Let the cake cool in the pan for 10-15 minutes before inverting it onto a wire rack to cool completely.
Step 8: While the cake cools, prepare the salted caramel glaze. In a heavy-bottomed saucepan, combine 1 cup granulated sugar and 1/4 cup water over medium heat. Stir until the sugar dissolves, then stop stirring. Cook until the mixture turns a deep amber color, gently swirling the pan occasionally (about 8-12 minutes).
Step 9: Remove the pan from the heat and carefully add the cubed butter, stirring until melted. The mixture will bubble vigorously. Slowly and carefully pour in the warm heavy cream, whisking continuously until smooth. Stir in 1 teaspoon vanilla extract and 1/2 to 1 teaspoon sea salt.
Step 10: Allow the caramel to cool slightly and thicken for about 10-15 minutes. It should be warm but pourable.
Step 11: Once the cake is completely cool, drizzle the salted caramel glaze generously over the top, letting it drip down the sides. Slice and serve immediately or store for later.