I found the inspiration for this recipe in The New England Yankee Cookbook, published in 1939. I bought it at a used bookstore in Houston, Texas, and changed it up just a bit.
3 eggs, beaten
1/2 cup maple syrup
2 cups whole milk
1/4 teaspoon salt
1/4 teaspoon nutmeg
In a bowl, combine all ingredients and mix well. Pour into 4 individual ramekins. Set ramekins in pan of hot water that comes halfway up sides of ramekins.
Bake at 350 degrees about 40 minutes, or until knife inserted in center of custard comes out clean. Serve warm or chilled.