Prepare the Cake Batter: Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. Cream together 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.

Combine Dry Ingredients: Whisk together the flour, baking powder, baking soda, and salt. Gradually add to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients.

Add Pecans: Fold in the toasted pecans.

Bake: Pour the batter into the prepared pans and bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.

Prepare the Caramel Glaze: Combine the brown sugar, butter, and heavy cream in a saucepan. Cook over medium heat, stirring constantly, until the mixture boils. Boil for 1 minute, then remove from heat and stir in the vanilla extract and salt.

Assemble: Pour the caramel glaze over the cooled cake, allowing it to drip down the sides. Sprinkle the top with chopped pecans.

Serve: Slice and serve the cake, enjoying the rich, buttery flavor with a nutty crunch.