Preheat oven to 350°F (175°C). Grease a 9-inch pie plate.
In a large bowl, whisk eggs until well beaten.
Add melted butter, milk, and vanilla extract to eggs, whisking to combine.
Gradually add sugar, Bisquick, and salt, whisking until smooth.
Stir in shredded coconut until evenly distributed.
Pour batter into prepared pie plate.
Sprinkle nutmeg on top if using.
Bake for 50-60 minutes until top is golden brown and center is mostly set.
Cool completely (about 1 hour) before serving.
Dust with powdered sugar and serve with fresh berries if desired.