Combine yeast and sugar in a bowl and then slowly pour in warm water while stirring everything together at the same time. Allow 10 minutes for the mixture to sit and the yeast to activate.
While waiting, melt the butter and milk together over stovetop on medium heat, stirring pretty consistently until the butter has melted. Be careful--you don't want it to be too hot or come anywhere close to a boil. Once butter has melted, set aside.
In a large bowl, stir flour and salt together. Next, combine butter mixture with yeast mixture and stir; then, add wet ingredients to dry ingredients and use your hands to knead the dough for approximately 3 minutes.
Line a separate large bowl with a small amount of coconut oil and then place the dough in the bowl. Cover it with plastic wrap and let sit for 1 hour, allowing the dough to rise and double in size. Alternatively, if your dough doesn't seem to be rising at room temperature, you can heat your oven to 200°, turn it off, and place the covered bowl (I used an oven-safe glass bowl) in the oven until the dough has doubled in size, approximately 1 hour.
While waiting, you can make the filling, which doesn't take long.
Melt butter and set aside. In a separate bowl, combine cinnamon and brown sugar and set aside. Other things you can do while waiting for the dough to rise include but are not limited to: walking your dog, catching up on emails, watching TV, sitting on Instagram--the possibilities are endless, and the time goes by faster than you'd think!
Once the hour has gone by and your dough has risen, preheat the oven to 350°. Next, add 1/4 cup flour to your dough and stir, which will help make the dough less sticky and easier to roll. Then, flour a baking mat and place the dough on the mat. Use a rolling pin to roll it out into a rectangle, approximately 9"x14", trimming the edges if needed. You want the rectangle to be big enough but you don't want the dough to be too thin. Otherwise, you'll have a difficult time rolling it.
Next, brush melted butter overtop of dough, leaving a 1" border around the edges. Next, spoon the cinnamon sugar mixture over top of butter and spread it evenly over the dough. Last, tightly roll up the dough long-ways.
Use a sharp knife (it helps to carefully flour the knife so it doesn't stick to the dough) to cut dough into 1.5" rolls, and then place the rolls into a large baking dish OR (what I did) was placed them into two greased 10" cake pans, cut side down.
Place a towel over the rolls and allow them to rise at room temperature for 30 minutes. I originally skipped this step, but after a lot of practice, I've found that it really does help in making your rolls nice and fluffy!
Once the rolls have doubled in size (or at least gotten significantly larger) brush rolls with a little more melted butter and then bake them for approximately 20 minutes.
While they're baking, make the glaze by combining all ingredients in a bowl and stirring with an electric mixer.
Remove rolls from oven, wait 5 minutes or so, and then drizzle glaze overtop.