Mix the overnight batter. In a large bowl, stir together the sourdough starter, pumpkin puree, milk, brown sugar, freshly milled einkorn flour, cinnamon, and optional nutmeg and cloves until just combined. The batter will be thick and stiff. Cover and let rest at room temperature for 8-12 hours, or overnight.
Finish the batter. In the morning, separate the eggs. Stir the yolks, melted butter, baking soda, baking powder, salt, and vanilla into the batter. Add additional milk as needed to loosen the batter until it is scoopable.
Whip the egg whites. In a clean bowl, whisk the egg whites until they form soft, fluffy peaks. Gently fold the whipped egg whites into the batter, being careful not to deflate them.
Cook the pancakes. Heat a griddle or large skillet over low heat. Lightly grease if needed. Scoop about 1/4 cup of batter per pancake and cook until bubbles form on the surface and the edges look set, then flip and cook until golden on the other side. Keep the heat relatively low so the centers cook through before the outsides burn. Keep finished pancakes warm on a platter in a 200°F (93°C) oven.
Make the maple icing drizzle. Whisk together the melted butter, maple syrup, powdered sugar, almond extract, and cream cheese until smooth. Add more maple syrup or powdered sugar as needed to reach a thick but pourable consistency. Drizzle over the warm pancakes just before serving.