In a small bowl, combine the filling of brown sugar and ground cinnamon. Distribute evenly over the surface, patting into the butter to help it stick, Drizzle the maple syrup evenly over the sugar, then roll up tightly lengthwise.

Using a serrated knife, slice into 9 equal-sized rolls. Place in a parchment paper-lined and buttered 8-9" pie plate or square baking pan.

Cover with plastic wrap and set aside in a warm environment for 2-3 hours, until doubled in size.

Preheat oven to 350F.

Remove the plastic wrap and drizzle with the 1/3 cup heavy cream, focusing on the centers of each cinnamon roll.

Bake for 25-35 minutes, until the tops are deeply golden. Let cool at least 10 minutes before adding the frosting.

In the bowl of a stand mixer, combine the softened butter and cream cheese. Beat until smooth. Add 1/2 cup powdered sugar, and beat until fluffy. Add the maple syrup and remaining powdered sugar. Beat until soft and fluffy, adding the heavy cream as needed to help loosen up the frosting. Add salt to taste.