Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine flour, sugar, baking powder, and salt.
Add milk, eggs, and melted butter to the dry ingredients. Mix until well combined.
In a separate bowl, mix the softened butter, brown sugar, and cinnamon for the filling.
Spread the filling mixture over the dough.
Roll the dough into a log and place it in a greased baking pan.
Bake for 45 minutes or until golden brown.
While the cake is baking, prepare the glaze by mixing powdered sugar, milk, and vanilla extract.
Once the cake is done, let it cool for a few minutes and then drizzle the glaze over the top.