Preheat oven to 375°F. Lightly grease a 9x9-inch baking dish or line with parchment.
In a large bowl, whisk together flour, sugar, baking powder, and salt.
Pour in milk and melted butter, then stir until a soft dough forms.
Turn dough out onto a floured surface and knead a few times until smooth.
Roll the dough into a 12x9-inch rectangle.
In a small bowl, combine softened butter, brown sugar, and cinnamon. Spread over dough.
Roll the dough tightly from the long edge and slice into 12 even pieces.
Place rolls in the baking dish. Bake for 11–13 minutes until golden brown.
While rolls bake, beat cream cheese until smooth. Add powdered sugar, milk, and vanilla. Beat until creamy.
Spread frosting over warm rolls and serve immediately (or hide a few for yourself!).