For the Cake:
Baking spray
3 cups (about 15 ounces) all-purpose flour
2 teaspoons baking powder
1 teaspoon baking soda
1 teaspoon salt
2 sticks (8 ounces) unsalted butter, softened
2 cups (about 14 ounces) packed light brown sugar
4 large eggs, at room temperature
1 tablespoon pure vanilla extract
1 1/4 cups buttermilk, at room temperature
8 ounces good quality white chocolate chips
1/2 cup coarsely chopped roasted, salted macadamia nuts

For the Salted Caramel Drizzle
1/2 cup (about 3 1/2 ounces) sugar
2 tablespoons light corn syrup
2 tablespoons water
2 teaspoons kosher salt
6 tablespoons heavy cream