Preheat the oven to 350°F (175°C). Grease and flour three 9-inch round cake pans.

In a bowl, combine the flour, baking soda, and salt. Set aside.

In another bowl, cream together the softened butter and sugar until light and fluffy.

Beat in the eggs one at a time, then stir in the vanilla.

Gradually add the flour mixture to the creamed mixture alternately with the buttermilk, beginning and ending with the flour mixture. Mix until just combined.

Divide the batter evenly among the prepared cake pans.

Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.

Let cool in pans for about 10 minutes, then remove from pans and cool completely on a wire rack.

In a saucepan over medium heat, combine the brown sugar, evaporated milk, and butter. Cook, stirring, until the mixture comes to a boil.

Cook for another 2 minutes.

Remove from heat and stir in the egg yolks, vanilla, coconut, and pecans. Let cool until thickened.

Once the cakes are completely cooled, frost the top of one layer, add the second layer and frost on top, and then place the third layer on top and frost the entire cake.