White German Chocolate Cake

• 1 (4-ounce) bar white baking chocolate, chopped
• 2 1/2 cups all-purpose flour
• 1 teaspoon baking soda
• 1/4 teaspoon salt
• 1 cup butter (salted), softened
• 1 cup granulated sugar
• 4 large eggs, separated
• 2 teaspoons vanilla extract
• 1 1/4 cups buttermilk

Coconut Pecan Frosting

• 2 1/2 cups finely chopped pecans
• 3 (5-ounce) cans evaporated milk
• 1 1/4 cups granulated sugar
• 1 cup butter (salted)
• 2/3 cup firmly packed light brown sugar
• 5 large egg yolks, lightly beaten
• 3 1/2 cups sweetened shredded coconut
• 2 teaspoons vanilla extract