Prepare the Cinnamon Roll Dough, as instructed, adding the ground cardamom to the dough.
Follow the instructions to let the dough rise to double in size, then refrigerate the covered bowl of dough overnight.
Filling
Lightly brush the muffin pan cups with 2 tablespoons of the melted butter.
In a bowl, combine the granulated sugar with the cinnamon. Sprinkle the cinnamon sugar into the buttered pan, turning the pan to coat all the sides, then dump the excess cinnamon sugar out onto a clean work surface so you can scoop it back up to use later. By buttering and sugaring the muffin pan, the sugar will slightly caramelize around the sides of the buns as they bake, creating a lovely crisp, golden brown crust.
On a lightly floured surface, scrape the chilled dough out of the bowl, lightly flour the top of the dough, and gently press the air out. Roll out the chilled dough into a rectangle measuring approximately 12x18 inches. Brush 3 tablespoons of the melted butter over the cold dough.
Combine 1/4 cup of the cinnamon sugar with the 2 tablespoons brown sugar, and sprinkle it over the buttered dough. Lightly press the sugar into the dough.
Shaping
Using a rolling wheel pastry cutter or pizza cutter, cut the dough into 12 strips. Then roll up each of the strips to form 12 rolls.
Place the rolls into the prepared muffin pan. Set in a warm place for just 20 minutes to rest, until slightly puffed.
Bake
Meanwhile, preheat the oven to 350 F, and position a rack in the center of the oven.
Bake the rolls on the center oven rack for about 18-20 minutes. The rolls should be puffed, and the color will be a pale golden brown. Carefully remove the hot rolls from the pan and set them on a cooling rack to cool for several minutes.
When the rolls are cool enough to handle, brush them lightly with the remaining 2 tablespoons melted butter, then coat them generously in the remaining cinnamon sugar.
Serve warm or at room temperature.
Notes
Storage and ReheatingStore leftover rolls in an airtight container at room temperature for up to 3 days.Reheat individual rolls in the microwave at 50% power for about 30 seconds.