In a large mixing bowl, cream together unsalted butter, granulated sugar, and brown sugar. Use a hand mixer or stand mixer fitted with the paddle attachment, and mix until the mixture is light and fluffy. This usually takes about three to five minutes. Properly creaming the butter and sugar enhances the cookie’s texture, making them soft and chewy.
Add the egg, vanilla, and salt into the mixture, and beat until thoroughly combined. The egg will add moisture and help bind everything together.
Gradually mix in the all-purpose flour until a soft dough forms. Be careful not to overmix at this stage; just mix until the flour is incorporated.
In a separate small bowl, mix together the remaining brown sugar and ground cinnamon to create the filling mixture.
Divide the dough into two halves. Take one half and place it on a large sheet of waxed or parchment paper. Press the dough lightly to flatten it, then cover it with another sheet of paper. Roll the dough into an eight-inch square, which helps create even cookies.
Sprinkle half of the cinnamon-sugar mixture over this rolled dough, ensuring even coverage. Then, starting from one edge, tightly roll up the dough into a log. Wrap it in plastic wrap and refrigerate for at least one hour to firm it up. This step prevents the cookies from spreading too much when baking.
Repeat the same process with the second half of the dough.
After the dough has chilled, preheat your oven to 375°F (190°C). Line two cookie sheets with silicone baking mats or parchment paper to prevent the cookies from sticking.
Slice the logs into ¼ to ½ inch thick cookies. Make sure to place them evenly spaced on the prepared cookie sheet, about two inches apart.
Bake in the preheated oven for eight to ten minutes or until the edges are golden brown. The cookies should no longer look glossy on top. Once done, remove them from the oven and allow them to cool completely on a wire rack.
While the cookies cool, prepare the frosting by whisking together the powdered sugar, vanilla, and enough milk to create a drizzle consistency. Start with two tablespoons of milk and adjust as necessary.
Once the cookies are cool, drizzle the frosting over them for an added touch of sweetness and decoration. Enjoy your homemade Cinnamon Roll Cookies!