Preheat the oven to 350°F (175°C) and line a 9x13-inch (23x33 cm) pan with aluminum foil, leaving some overhang on the sides for easy removal. Grease the foil with non-stick spray.
Spread the chopped pecans, shredded coconut, and brown sugar in the prepared pan.
Sprinkle with cinnamon and salt, and drizzle with vanilla extract and melted butter.
In a medium bowl, beat together the softened butter and brown sugar until creamy. Add eggs one at a time, followed by vanilla, mixing until thoroughly combined.
Add baking powder and salt, mixing until incorporated. Add half of the flour, followed by milk, and then the remaining flour, mixing well after each addition.
Pour the batter over the pecan mixture in the pan and bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 5 minutes, then use a knife to loosen the sides. Invert the cake onto a platter using the foil overhang and let cool for 15 minutes before serving.
