Preheat your oven to 325 degrees F. Spray the bottom and sides of a 9x13" with with nonstick spray. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, combine the sugar, brown sugar, milk powder, and salt. Mix on low speed until evenly blended.
With the mixer on low speed, add the melted butter and stir for one minute until all the dry ingredients are wet.
Add the heavy cream and vanilla and continue mixing on low speed for about one minute, until any of the white streaks from the cream have completely blended into the mixture. Scrape down the sides of the bowl with a spatula.
With the mixer on low speed, add the egg yolks, stirring them into the mixture until combined. Be careful not to over beat (aerate) the mixture, but certain the mixture is glossy and homogenous.
Pour the filling into the prepared pan and bake for 8 to 10 minutes. You want the filling to be firmer and more set toward the outer edges of the baking pan but slightly jiggly and loose in the center. If the filling is still jiggly all over, give it another 2 to 3 minutes. But it's going to be soft! Once you add the coconut and pecans, and cools, it starts to set a little and will thicken.
Let the filling cool slightly and add the toasted coconut and toasted pecans. The filling can be used immediately or stored in an airtight container in the refrigerator.