Preparation Steps

• Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans and line the bottoms with parchment paper.
• In a medium bowl whisk together the flour, baking powder, baking soda, and salt until evenly combined.
• In a large bowl, cream 0.5 cup of the softened butter with the granulated sugar until light and fluffy, about 3 to 4 minutes.
• Add the eggs one at a time, beating well after each addition, then mix in the vanilla extract.
• Alternate adding the dry ingredients and buttermilk to the butter mixture, beginning and ending with the dry ingredients. Mix until just combined; do not overmix.
• Divide the batter evenly between the prepared pans and smooth the tops. Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.
• Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely while you make the caramel frosting.
• For the frosting, combine the brown sugar, remaining 0.25 cup butter, and evaporated milk in a medium saucepan. Bring to a boil over medium heat, stirring constantly. Once boiling, reduce heat and simmer for 4 to 5 minutes, stirring, until slightly thickened.
• Remove the caramel from heat and let cool 8 to 10 minutes. If desired, whisk in powdered sugar a little at a time to reach a spreadable consistency, then stir in the 0.25 tsp salt and 1 tsp vanilla if extra flavor is desired.
• Place one cake layer on a serving plate, spread a thin layer of caramel frosting, top with the second layer and pour or spread remaining frosting over the top and sides. Allow frosting to set before slicing. Serve at room temperature.