Green Apple-Sourdough Pancakes

For the Sourdough Starter:

1 cup whole milk

1 teaspoon active dry yeast (1/2 packet)

1/2 cup apple cider

3 tablespoons packed light brown sugar

2 tablespoons unsalted butter, melted

1 cup all-purpose flour

For the Pancakes:

1/2 cup all-purpose flour

1 large egg, slightly beaten

1 teaspoon baking soda

1 small tart green apple (such as

Granny Smith), unpeeled, diced

1 to 2 tablespoons unsalted butter

Maple syrup or honey, for serving

Chopped pecans, for garnish (optional)