Prepare Cinnamon Filling: In a medium bowl, combine melted butter, brown sugar, and ground cinnamon to create the filling. Mix until smooth and transfer to a ziplock bag. Allow to thicken for about 10-15 minutes while preparing the pancake batter.

Make Pancake Batter: In a large mixing bowl, whisk together flour, baking powder, and salt. In a separate bowl, whisk together milk, oil, and beaten egg. Gradually pour wet ingredients into dry mixture, stirring gently until just combined.

Make Cream Cheese Glaze: In a microwave-safe bowl, heat cream cheese and melted butter for 20-30 seconds. Whisk until smooth, then add powdered sugar and vanilla extract, whisking until silky.

Cook Pancakes: Preheat a skillet over low to medium heat. Pour ½ cup of batter onto skillet and pipe cinnamon filling in decorative swirls. Cook for 2-3 minutes until bubbles appear, then flip and cook another 1-2 minutes until golden.

Serve: Stack pancakes on a plate, drizzle with cream cheese glaze, and sprinkle with powdered sugar, chopped nuts, or fresh berries if desired. Serve immediately.