Step 1: Preheat and Prepare the Pan

1. Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish with butter or non-stick spray.

Step 2: Make the Cake Batter

1. In a large mixing bowl, whisk together the flour, sugar, salt, and baking powder.
2. Add the milk, eggs, and melted butter to the dry ingredients. Mix until smooth and well combined, but avoid overmixing. Pour the batter into the prepared baking dish and spread it out evenly.

Step 3: Prepare the Cinnamon Filling

1. In a medium bowl, combine the brown sugar, cinnamon, and softened butter. Mix until smooth and creamy.
2. Drop spoonfuls of the cinnamon filling over the cake batter. Use a knife or skewer to swirl the filling into the batter, creating a marbled effect.

Step 4: Bake the Cake

1. Bake the cake in the preheated oven for 30–35 minutes, or until a toothpick inserted into the center comes out clean.
2. Remove the cake from the oven and allow it to cool slightly while you prepare the glaze.

Step 5: Make the Cream Cheese Glaze

1. In a medium bowl, beat the softened cream cheese until smooth. Add the powdered sugar, milk, and vanilla extract. Whisk until the glaze is smooth and pourable. If needed, add an extra tablespoon of milk to reach the desired consistency.

Step 6: Glaze the Cake

1. Drizzle the cream cheese glaze over the warm cake, spreading it evenly with a spatula or the back of a spoon.
2. Let the glaze set for a few minutes before slicing and serving.