In a large bowl or stand mixer, cream butter and sugar until combined. Add egg, vanilla and buttermilk. Mix just until combined. In another bowl, sift together, flour, baking powder, baking soda and salt. Add to wet ingredients in two batches and mix just until a soft dough forms. Turn out onto a flour surface and flatten into a disc. Wrap in plastic wrap and refrigerate at least 2 hours or overnight.

Take dough out of refrigerator and place on a floured surface or board, press or roll out into a large rectangle, about 9 x 12. In a small bowl mix brown sugar and cinnamon. Brush cookie dough with melted butter and sprinkle brown sugar/cinnamon mixture over the top leaving the edges bare. Carefully roll long end like a jelly roll and tuck ends under. Place on a sheet pan and loosely cover with plastic wrap. Freeze for 30 minutes to one hour.

Preheat oven to 350 degrees Fahrenheit. Take dough out of freezer and allow to stand 5 minutes. Remove plastic wrap and slice cookies starting at the end. Shape cut ends into cookies and place on a parchment lined cookie sheet. Pay careful attention to make sure seams are sealed. Bake at 350 degrees for 10-12 minutes. Cool 2 minutes on pan and move to cooling rack.

In a small bowl combine powdered sugar, cream cheese, butter and vanilla. Add milk a little at a time until smooth icing forms. Spread or brush with glaze and allow glaze to set up for 5 minutes. Enjoy!