In a small bowl, combine all purpose flour, salt, and baking powder and whisk.
In the bowl of a stand mixer, cream butter and sugar together until light and creamy, for about 2-3 minutes.
Beat in the egg and vanilla extract.
Slowly pour the flour mixture into the stand mixer while it is running and mix until a soft dough forms.
Add more flour if needed.
Cut a sheet of parchment paper and lay it on a clean work surface.
Dust with flour and turn cookie dough out onto it.
Divide in two, placing one half back in the bowl until ready to use.
Roll out the dough into a large rectangle until it about 1/4 inch thick.
Brush half of the melted butter onto the dough.
In a small bowl, whisk together sugar and cinnamon.
Sprinkle half of the cinnamon sugar mixture over the dough and tightly roll it up.
Repeat with the second half of dough.
Cover with plastic wrap and chill in the fridge for 2 hours.
When ready to bake, preheat oven to 350 degrees F and line a cookie sheet with parchment paper.
Remove plastic wrap from the dough and slice cookies about 1/2 inch thick.
Lay cookies on the prepared cookie sheet (10-12 cookies per pan) and bake for 10 minutes.
Let cool slightly before moving the cookies to a wire cooling rack.
Allow cookies to cool completely.
To prepare the icing, beat powdered sugar, heavy cream, and vanilla extract together in a small bowl using a hand mixer.
Drizzle onto the cookies and serve.