Preheat your oven to 350°F (175°C).

Grease and line two round cake pans with parchment paper.

In a bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition.

Stir in the vanilla extract.

In a separate bowl, whisk together the dry ingredients: baking soda, salt, baking powder, and cake flour.

Gradually add the dry ingredients to the wet mixture, alternating with buttermilk. Mix until just combined.

Divide the batter evenly between the prepared pans.

Smooth the tops with a spatula.

Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

Allow the cakes to cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.

In a saucepan over medium heat, melt the butter.

Stir in the brown sugar and vanilla extract.

Add the agave syrup and a pinch of salt.

Simmer for 5-7 minutes until thickened.

Let the caramel cool slightly before using.

In a large bowl, beat the butter until creamy.

Gradually add the sifted powdered sugar and salt.

Mix until smooth and fluffy.

Level the cooled cakes by cutting off any domed tops.

Spread a layer of buttercream on the first cake layer.

Drizzle caramel sauce over the frosting.

Place the second cake layer on top and apply a thin crumb coat of frosting.

Chill the cake for 10 minutes, then apply the final layer of frosting.

Drizzle more caramel sauce over the top for a stunning finish.