Add sugar, yeast and milk into the bowl of a stand mixer. Allow to foam up, about 5-10 minutes
With the mixer on low speed add the egg. Gradually add in flour until the
dough forms a ball and is no longer sticky. Knead for 5-10 minutes until the dough is stretchy with only a slight
stickiness to the touch. It should easily come off of the dough hook.
Arrange dough into a rectangle and cover with plastic wrap. Allow to rest in the fridge for 1 hour.
Prepare your butter mixture. Place 3/4 of a cup of butter (3 sticks) into your stand mixer. Add 1 cup of brown
sugar and 3 tsp of cinnamon. Mix until all loose sugar and cinnamon is combined. You’re not trying to cream the butter here, so do not over mix. It’s over to have chunks of butter as long as all the loose pieces are combined.
Roll out dough to roughly 10 x 16 inches . Place the chilled butter mixture on top of the rolled out dough.
Fold the dough into 3 parts like you would fold a letter. Left 2/3 of the way, right over top of the last 3rd. Roll out
again and fold the same way from the short side. Complete the process one last time. Wrap in more saran and let
chill for 1 more hour minute
Grease your muffin pans with butter. I used a taller muffin pan to get more height.
When the dough is chilled, roll it out to another 10×16 rectangle. Cut strips from the long end. Roll the strip so it creates a tall spiral. Place in your greased pan making sure there is an even base so the cruffins will stand once baked.
Let your buns rise in the pan for 1- 3 hours. They won't double but they will expand. Cover with a damp towel to keep the moisture in the dough.
Heat oven to 400F.
Bake for 20-25 minutes, or until golden brown.
Once done, set pans on a wire rack to cool in pan.
In a sauce pan over medium heat, combine sugars, sweetened condensed milk and water. Cook until a dark caramel colour, whisking constantly so the bottom does not burn. Watch carefully as it's easy to go from perfect to burnt.
Transfer caramel to a bowl and chill.
The the bowl of a stand mixer fitted with a whisk attachment, whip butter and caramel together until thick and airy.
Use a chopstick or knife to create a whole in the middle of your bun.
Fill a pastry bag with butter and pipe into the hole. Do this slowly so you can fill the entire whole without it exploding out the side.
Dust with icing sugar to finish.