Pre-heat your oven to 325 °F. Spray a 9x13 pan generously and set aside.
In a small bowl combine softened butter, brown sugar and cinnamon until it forms a crumbly mixture. Set aside.
In a large bowl mix together flour, sugar, baking powder, and salt.
Cut in the softened butter, then stir in milk to form a soft dough.
Roll out the dough on a lightly floured surface into a rectangle about 1/2 inch thick.
Spread the filling on the rolled out dough.
Roll up the rectangle. With a sharp knife slice into 12 rolls. Place the rolls cut side up into the pan.
Bake in the oven for 30-35 minutes or until they are browned and done. If you find they are not browning, turn up the oven to 350 °F. Remove from the oven once they are fully baked.
Make a batch of The Best Danish, Pastry and Cinnamon Roll Icing Glaze and drizzle on top of the cinnamon rolls.
Notes
By cooking them at a lower temp you are giving the baking powder time to rise, which is what makes these fluffy!