3sticks (¾ pound or 339 g)butter, cold and cut into ¼-inch thick slices
⅓cup (75 g)butter, melted
1cup plus 2 tbsp (250 g)packed light brown sugar
FROSTING (IF DESIRED)
4ounces (113 g)cream cheese, softened
4tbsp (½ a stick or 57 g)butter, softened
2cups (250 g)powdered sugar
1tspvanilla extract or vanilla bean paste
SUGAR DIP (IF DESIRED)
½cup (100 g)granulated sugar
Preheat oven to 350° F. Spray muffin tins with nonstick baking spray and set aside.
In a large bowl, measure flour. Add baking powder, baking soda, and salt and mix well. Add butter pieces and, with fingers, press and smoosh butter into flour mixture until butter pieces are about the size of large marbles.
Combine eggs and buttermilk in a separate bowl and whisk to mix well. Add all of this mixture into the flour mixture and stir until all of the flour mixture has been incorporated and dough comes together.
Press on top of the dough with your palms and cover the bowl with plastic wrap. Refrigerate it for at least 30 minutes, or up to a couple of days.
Make the filling by mixing the brown sugar and cinnamon in a medium bowl with a whisk. Set this aside.
Dump dough out onto a well-floured surface and knead very briefly until dough comes together. Roll out to about a ½-inch thick rectangle and fold top ⅓ of dough over onto itself, and bottom ⅓ over onto the top ⅓, just like folding a business letter. This will allow for layers in the dough.
Now roll the dough out into a large rectangle that's about 20 inches wide by 18 inches long, ¼-⅛ inch thick.
Brush melted butter all over dough to completely cover edge to edge. Sprinkle filling all over dough and use hands to press it lightly into butter to adhere.
Roll up dough, beginning on the long (wide) edge. Pinch the seam to seal at the end of rolling and cut the dough in half using a sharp knife or bench scraper. Cut each half in half again to make 4 large pieces. Taking your knife or bench scraper, mark 2 markings in each piece to cut 3 equal-sized pieces.
Place each roll into prepared muffin pans. Place the muffin pans on a larger baking sheet (or place a very large piece of tin foil on rack in the oven) to catch any filling from bubbling over.
Bake rolls for about 25 minutes, or until well risen and nicely browned.
To make frosting, combine all frosting ingredients in a large bowl until well incorporated and smooth.
Remove from the oven and allow to cool in the muffin tins for about 5-10 minutes before removing from the muffin wells. Frost as desired, or tip over and dip edges into a bowl of granulated sugar. These rolls are best served warm from the oven, but can be reheated in a low temperature oven (300° F) for about 10 minutes. They can be frozen without frosting for about 2 months, well wrapped. Defrost and then reheat as desired and frost as desired.