Preheat oven to 325 degrees. Line a 9x13 baking dish with foil or parchment paper, letting the edges hang over the edges--then spray with cooking spray.
Spread the nuts on a rimmed cookie sheet, or in a pie plate. Toast in the oven until very lightly browned, about 5-8 minutes. Set aside to cool.
In a medium saucepan, whisk together the egg yolks, salt, and sugar over medium-low heat. Once they're combined, whisk In the butter until melted, then gradually whisk In the heavy cream and vanilla.
Cook over low-medium heat, stirring constantly, until it starts boiling, begins to thicken, and gets to 180 degrees on a thermometer. (About 5-6 minutes for me.) Once It does, remove from heat and stir in the toasted pecans and coconut.
Spread the topping evenly over the cooled brownies. Cover with foil and chill for one to two hours…OR…cut them right away and eat them warm! (Which we do…we can never wait!) Cut into bars for serving. If you're eating them warm, try serving them with vanilla ice cream. Trust me, it's crazy good, and worth every single calorie!
My favorite brownie mixes to use are Pillsbury and Ghirardelli.
The frosting recipe covers a 9×13 pan of brownies. If you’re making an 8×8 or 9×9, you can halve the recipe, or even do 3/4 of the recipe if you like extra frosting like I do!