Cinnamon-Bun Filled Pancakes

Source: Williams-Sonoma Kitchen
adapted by http://theresalwaysthyme.blogspot.com

for the cinnamon filling:
1/2 cup granulated sugar
2 tablespoons all-purpose flour
1 1/2 tablespoons ground cinnamon
1/4 teaspoon salt
4 tablespoons (1/2 stick) unsalted butter, cut into 1/2-inch cubes, at room temperature

for the cream cheese frosting:
3 oz. cream cheese, at room temperature
4 tablespoons (1/2 stick) unsalted butter, at room temperature
1 1/2 cups confectioners' sugar
3 to 4 tablespoons milk

for the pancakes:
2 cups all-purpose flour
1 teaspoon baking powder
1/2 teaspoon salt
1 tablespoon granulated sugar
4 eggs, separated
2 cups milk
4 tablespoons (1/2 stick) unsalted butter, melted, plus more for cooking

To make the cinnamon filling: In a bowl, still together the granulated sugar, flour, cinnamon and salt. Add the butter and, using the back of a spoon, mash the butter into the flour mixture until all of it is absorbed into the butter, forming a paste. Set the cinnamon filling aside.

To make the cream cheese frosting: In the bowl of an electric mixer fitted with the flat beater, beat together the cream cheese and butter on medium speed until light and fluffy, 2 to 3 minutes. Add the confectioners' sugar, reduce the speed to low and beat until combined, 1 to 2 minutes, stopping the mixer occasionally to scrape down the sides of the bowl. Add 3 tablespoons of the milk and beat until combined, about 1 minute. The frosting should be thick but still pourable; add more milk if needed to thin it. Transfer the frosting to a small bowl; set aside.

To make the pancakes:
In a bowl, whisk together the flour, baking powder, salt and granulated sugar. In another bowl, lightly whisk the egg yolks, then whisk in the milk and the 4 tablespoons melted butter. Whisk the egg yolk mixture into the flour mixture until well combined; the batter will be lumpy. Using an electric mixer fitted with the whisk attachment, beat the egg whites on high speed until stiff but not dry peaks form, 2 to 3 minutes. Using a rubber spatula, gently fold the whites into the batter in two additions.

Put 1/8 teaspoon melted butter in each well of a filled-pancake pan. Set over medium heat and heat until the butter begins to bubble. Pour 1 tablespoon batter into each well. Spoon 1/2 teaspoon of the cinnamon filling into the center of each pancake and top with 1 tablespoon batter. Cook until the bottoms are golden brown and crispy, about 3 minutes. Using 2 skewers, flip the pancakes over and cook until golden and crispy, about 3 minutes more. Transfer the pancakes to a plate. Repeat with the remaining batter and filling.

Drizzle the pancakes with the frosting and serve immediately. Makes 35 to 40.