Flour a clean surface and roll out the dough to 1/2" thickness, in the shape of a large rectangle.
Brush with 1/4 cup of butter on the dough.
In a small bowl, combine the brown sugar and cinnamon and sprinkle all over the cookie dough.
Roll the cookie dough into a log, long end to long end.
Refrigerate for 1 hour or overnight.
Preheat oven to 350F and remove the cookie dough log from the fridge.
Line two cookie sheets with parchment paper or silicone liners.
Trim off the edges (about 2-3") and discard. Slice the remaining dough into 1/4" thick slices.
Place the slices on a parchment paper-lined cookie sheet (or silicone mat-lined) at least 1" apart.
Bake for 8-12 minutes, until just slightly golden on the edges.
Notes
Chill for clean slices: After rolling the dough into a log, refrigerate for at least 1 hour (or overnight). This firms it up and makes slicing easier without squishing the swirl.
Use unflavored dental floss to slice: For perfect rounds, slide floss under the log, cross the ends over the top, and pull tight. It’s cleaner than a knife and keeps the shape intact.
Don’t skip the butter brush: Brushing the dough with softened butter helps the cinnamon-sugar stick and creates a gooey, caramelized swirl during baking.
Watch the bake time: Bake just until the edges are lightly golden. Overbaking can dry them out—these cookies are best when soft and tender.
Add a glaze for extra flair: Drizzle cooled cookies with a simple vanilla glaze (powdered sugar + milk + vanilla) for a cinnamon roll finish that looks bakery-worthy.