Preheat your oven to 325°F (163°C). Grease and flour a Bundt pan. In a large mixing bowl, beat the butter and sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In another bowl, whisk together the flour, baking powder, baking soda, and salt. Gradually add the dry ingredients to the butter mixture, alternating with buttermilk. Mix until just combined.

Pour the batter into the prepared Bundt pan. Bake for 50–55 minutes or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 10 minutes before inverting onto a wire rack.

While the cake is cooling, melt butter in a saucepan over low heat. Stir in sugar and water, then cook until sugar dissolves. Remove from heat and mix in vanilla extract.

Poke small holes all over the warm cake using a skewer or fork. Slowly pour the butter sauce over the cake, allowing it to soak in completely.

Drizzle caramel sauce over the cake, then sprinkle with sea salt for a perfect sweet-and-salty balance.