In a small bowl, stir together the melted butter, brown sugar, cinnamon, and flour until smooth. Let the mixture stand for about 5 minutes, until slightly thickened but still pipeable.

Transfer the cinnamon mixture to a piping bag or sturdy zip-top bag. Press out excess air and seal the bag. Set it aside with the tip uncut while making the pancake batter.

In a large bowl, whisk together the flour, granulated sugar, baking powder, baking soda, and salt. Break up any compacted flour and distribute the leavening evenly.

In a medium bowl, whisk the buttermilk, eggs, melted butter, and vanilla until smooth and evenly blended.

Pour the wet ingredients into the dry mixture: Fold gently with a flexible spatula just until no large dry pockets remain. Small lumps are expected. The batter should be thick but pourable; overmixing can make the pancakes tough.

Let the batter stand at room temperature for 10 minutes. It should become slightly thicker and show small bubbles across the surface. Do not stir it vigorously after resting.

Heat a large nonstick skillet or griddle over medium-low heat. Add about 1/2 teaspoon of the neutral oil and wipe it into a very thin layer. The pan is ready when a drop of water sizzles gently rather than evaporating immediately.

Snip a small opening, approximately 1/8 inch (3 mm), from one corner of the bag. A large opening can release too much filling and create thick areas that burn before the pancake cooks.

Scoop about 1/3 cup (80 ml) of batter onto the skillet for each pancake. Leave several inches between them so they are easy to turn. Cook only two or three at a time unless using a large griddle.

Cook for 1 to 2 minutes, until bubbles appear near the edges and the surface begins to lose its wet shine. Pipe a thin cinnamon spiral over each pancake, starting near the center and stopping at least 1/2 inch (1.25 cm) from the edge.

Continue cooking for about 30 seconds, then slide a thin spatula fully beneath each pancake. Turn it quickly but gently. Cook the cinnamon side for 1 to 2 minutes, until the pancake is cooked through and the swirl is caramelized but not burned.

Transfer the pancakes to a wire rack or baking sheet with the cinnamon side facing upward. Carefully wipe caramelized sugar from the skillet with a damp paper towel held in tongs before starting the next batch. Add another thin coating of oil as needed.

Repeat with the remaining batter and filling, adjusting the heat if the cinnamon begins darkening too quickly. The pancakes should be golden, spring back lightly in the center, and show no wet batter along the edges.

Beat the softened cream cheese until smooth: Add the powdered sugar, milk, vanilla, and salt, then whisk until the glaze is thick but pourable. Add additional milk 1 teaspoon (5 ml) at a time if needed.

Arrange two warm pancakes on each plate with the cinnamon sides facing upward. Drizzle with the cream cheese glaze and serve immediately.