Preheat the oven to 350°F and grease an 8x8-inch square baking pan.
Heat the milk and butter in a small saucepan over medium-low heat until the butter is melted and the milk is steaming. Set aside.
In a large bowl, whisk together eggs, sugar, vanilla, and salt until light and fluffy.
Add flour and baking powder to the bowl, then fold in the dry ingredients until combined. Pour in the warm milk and butter mixture and fold to create a smooth batter.
Transfer the batter to the prepared pan and bake for about 30 minutes, or until the cake is puffed and golden.
Meanwhile, prepare the topping by melting butter in a saucepan. Mix coconut, brown sugar, cream, salt, and melted butter in a bowl.
Once the cake is baked, spread the topping evenly over it and broil for about 3 minutes, until bubbly and golden.
Allow the cake to cool on a wire rack before slicing and serving.