In a medium bowl, whisk together the flour, baking powder, and salt.
Pour the buttermilk, oil, and egg into the dry ingredients. Then mix just until batter is moistened, a few small lumps are fine. Set aside.
In a medium bowl, mix together the butter, brown sugar, and cinnamon until a paste forms. Pour the filling into a Ziploc bag and cut a small hole in the corner of the bag. Set aside in a cool place. (It should have a toothpaste-type consistency.)
Cream Cheese Glaze
In a small saucepan, heat the butter and cream cheese over medium heat until melted and smooth. Whisk in powdered sugar and vanilla extract. Remove from heat and set aside to cool a bit.
Heat a large skillet over medium-low heat and spray with nonstick spray. You want the heat low so the cinnamon filling doesn't burn.
Scoop about 3/4 cup of pancake batter onto the skillet.
When the pancake has started to cook a little, pipe in the cinnamon filling onto the pancake batter in a swirl pattern starting at the center and working your way out.
When bubbles begin to appear on the surface of the pancake, carefully flip it over with a thin spatula/ Continue to cook until browned on the underside, about 1 to 2 minutes.
Transfer the pancake to a baking sheet or platter and keep it in a warm oven (200 F) until ready to serve.
To serve, spoon warm cream cheese glaze over the top of each pancake and sprinkle with powdered sugar if desired.
You can substitute sour milk if you don't have buttermilk. Mix together 1 cup of milk + 1 tablespoons white vinegar and let sit for a few minutes. OR you can substitute plain milk.
This recipe makes more cream cheese glaze than we usually use for our pancakes. Store any extra in the fridge and heat in the microwave until runny when you're ready to use it.