On a small baking sheet, toast pecan halves in a 350F oven for 7-8 minutes until roasted and fragrant. Remove and allow to cool. Chop before using. 1 cup (114 g) pecans
Place butter in a medium saucepan and melt over medium-high heat. 8 tablespoons (1 stick, 113 g) unsalted butter
Add granulated sugar, brown sugar, evaporated milk, and salt. Stir and bring to a full boil. ½ cup (100 g) granulated sugar ½ cup (107 g) packed light brown sugar 2/3 cup (180 ml) evaporated milk ¼ teaspoon salt
Continue to boil for 3 minutes more, until slightly thickened.
Remove the pan from the heat and stir in the vanilla extract. 1 teaspoon vanilla extract
Stir in ¾ cup of the toasted pecans and the coconut. 1 cup (85 g) lightly packed sweetened shredded coconut
Using a wooden skewer or the handle of a wooden spoon, poke holes all over the surface of the cake that go most of the way through the cake (but don't hit the bottom) that are about 1 inch apart (the skewer may get a bit sticky with moist cake crumbs.
Spread the coconut pecan frosting over the hot cake and smooth gently.
Sprinkle over the remaining pecans. Let cool and set completely before slicing and serving, at least 2 hours.