Add the warm milk to a large bowl along with the sweetened condensed milk and an egg. Whisk these together.
Add the yeast, white sugar and powdered monkfruit sweetener to the bowl as well. Whisk again then cover with plastic wrap for ~3min or until the yeast is foamy.
Add the Keto Flour and salt and begin to mix everything with a spatula until a cohesive dough forms.
Transfer the dough to a clean, greased surface and begin to knead it for about 3 minutes or just until the dough becomes more smooth and elastic and less sticky.
Use your hands to flatten the dough out a bit, then spread the 1/4 cup softened butter on top.
Try your best to fold the dough around the butter, then begin kneading again. It will be a bit messy but continue to knead the dough until it again becomes smooth and elastic and the butter is fully incorporated. (Use a spatula or dough scraper to collect any stuck pieces of butter/dough as you go along).
Form the dough into a ball and place it in a large buttered bowl, turning it to coat all sides with butter.
Cover the bowl with plastic wrap and set it somewhere warm to rise for ~ 1.5 hours (see tips for where I set mine).
After the dough has risen slightly, pour it out onto a greased surface and place a large piece of greased parchment paper on top (this prevents the rolling pin from sticking). Roll the dough out into a ~9x12 rectangle, kind of like you are making cinnamon rolls.
Roll the dough up from length to length, folding the side in as you go. Once rolled, I like to kind of press the ends in to make the roll a little shorter/thicker.
At this point, you can also grease a loaf pan with butter.