In a small saucepan, heat the milk beverage and 4 T. of the maple sugar over low heat until the mixture reaches a temperature of 100-110℉. Remove from the heat, sprinkle the yeast over the milk, and gently stir it in. Set it aside for 5-10 minutes until the mixture becomes frothy.
Meanwhile, place the gluten-free flour, salt, and remaining 2 T. of sugar in the bowl of a stand mixer fitted with the paddle attachment. Mix together the flour, salt, and sugar on low.
Line an 8x8" or 7x11" glass baking pan with parchment paper. Cut an additional piece of parchment paper that is about 17" long, this is what you will roll the dough out on.
Once the yeast has proofed, proceed with making the dough. Add the yeast/milk, melted butter, egg, and warm water to the flour in the bowl of the stand mixer. Turn the mixer on low and let it mix for about 1 minute. Stop the mixer and scrape down the sides of the bowl. Turn the mixer back onto medium speed and allow it to mix the dough for 3-4 minutes. This will create a smooth dough that is slightly sticky.
Prep the cinnamon roll filling ingredients while the dough is mixing. Melt the butter and set it aside. Combine the coconut sugar and cinnamon in a small bowl and set it aside.
To roll out the dough, sprinkle about 3 T. of flour on the 17" long piece of parchment paper you cut. Using a soft spatula, scrape the dough out onto the pachment paper. It should hold its shape but still be slightly tacky.
Generously flour your hands and begin to press the dough out into a rectangle that is about 9" tall and 17" long. Make sure there is plenty of flour under the dough as you press it out to prevent it from sticking when you go to roll the dough.
Spread the melted butter over the rectangle. Sprinkle the cinnamon sugar mixture over the melted butter. Make sure both the butter and cinnamon sugar reach all the way to the edges of the dough.
Use a pizza cutter to cut the rectangle into 6 strips that are 17" long. Each strip will be about 1.5" tall/wide.
Roll each strip into a cinnamon roll. If the strip starts to stick to the parchment paper as you roll it up, just use floured hands to scrape up the dough and keep rolling. Place the roll, swirl side up, in the parchment paper lined baking pan. Repeat with the remaining strips, placing each cinnamon evenly spaced apart in the pan.
Note: If you like tall cinnamon rolls, leave the rolls as they are. If you like fatter, squat cinnamon rolls, gently press down the cinnamon rolls in the pan with the palm of your hand.
Cover the pan with lightly oiled plastic wrap and place it in a warm location (around 70℉ is ideal). Let the rolls proof for 30-90 minutes.**See Notes for overnight option.** The rolls should be puffy and about doubled in size.
Preheat the oven to 350°F while the rolls are proofing. Once the rolls have proofed, remove the plastic wrap and spread about 2 tsp. of heavy cream over each roll. Cover the pan with an aluminum foil cover.
Bake for 15 minutes. Remove the aluminum foil cover and bake for an additional 15-20 minutes. The rolls should be puffy and lightly browned. A toothpick inserted into one of the center rolls should come out clean with only a few crumbs.
Remove the rolls from the oven and allow them to cool for 10-15 minutes before topping them and serving them!
Store leftover rolls in an airtight container at room temperature. To get leftover cinnamon rolls to be fluffy again, reheat them in a microwave oven or toaster oven.