In a medium bowl, whisk together the flour, sugar, baking powder and 1 teaspoon salt. In a small bowl, whisk together the buttermilk, butter and egg. Stir the wet mixture into the dry; the batter will be thick.
Heat a 9-inch cast-iron skillet over medium heat. Add the cream and maple syrup and whisk to combine. Bring to a low simmer and add a pinch of salt. Turn off the heat. Use a soup spoon to drop the cake batter onto the maple syrup mixture.
Bake until the cake is set, 40 to 45 minutes. Serve with whipped cream or vanilla ice cream, if desired.