Begin by pouring milk and butter into a microwaveable bowl. Microwave on high for about 2 minutes or until the butter begins to melt.
Monitor the temperature of the milk and butter. It needs to come down to 110℉ before it can be mixed with the yeast, or it will kill the yeast.
Once the milk butter mixture is 110℉, pour it into a stand mixer.
Add the instant yeast and sugar. Allow to rest for a few minutes until the yeast starts to foam.
Add the eggs, bread flour, and sea salt to the mixer.
Using the dough hook attachment, knead the dough on low speed for 10 minutes.
Cover the dough and allow to rise for 1 hour.
After the dough has risen, punch down the dough and form it into a rough square shape.
Using the rolling pin, roll the dough out to approximately 24x12 rectangle.
Spread the softened butter onto the dough using a pastry brush. The butter should be very soft, but not totally melted. It can be microwaved for a few seconds to achieve the softened texture.
Mix the brown sugar and cinnamon in a small bowl.
Evenly spread the cinnamon sugar mixture over the buttered dough.
Roll the rectangle into a log shape that is 24 inches long.
Cut the log in half, then each half into half, then each quarter into thirds. This will make a dozen cinnamon rolls. You can also measure and cut every 2 inches, but I find it easier to cut without measuring.
Place the cinnamon rolls into a greased 13x9 baking dish. Cover with plastic wrap and refrigerate overnight.