Combine Cinnamon Filling. In a small bowl, combine brown sugar with cinnamon, vanilla powder (if using), and a pinch of salt. Mix until well blended, to evenly distribute the cinnamon into the sugar.
Roll Out. Lay down a sheet of parchment paper or very lightly flour your countertop. Transfer the dough from the bowl to your parchment or counter and cover with another sheet of parchment paper. Use a rolling pin to roll the dough out into a 15-inch square (15"x 15").
Fill The Rolls. Spread Softened Butter over the 15-inch dough square in an even layer. The butter should be VERY soft so it's easily spreadable. If you can't get the butter soft enough, you can melt it and cool it slightly before spreading. Sprinkle the cinnamon brown sugar mixture over the butter in an even layer.
Form The Rolls. Use a sharp knife or pizza cutter to cut the dough into twelve (1.25-inch) strips. Roll each strip up to form a roll, starting at one end and tightly rolling to make a spiral as you go. (We find this method works MUCH better with gluten-free sweet rolls than the traditional rolling the dough into a long cylinder and slicing or using floss to cut them.) Place rolls into a greased 9x13-inch pan.
Cover & Rise. Then, cover the pan with plastic wrap and set in a warm place to rise 45-60 minutes. They'll look puffy but won't double in size at this point. Preheat the oven to 350 degrees as the cinnamon rolls rise.
Bake. Remove the plastic wrap from the pan, then bake cinnamon rolls in preheated oven 30-35 minutes, or until golden brown on top. The interior of the dough should read at least 190-200 degrees F. Set rolls aside to cool for 15-20 minutes, while you make the glaze.