Making the Dough-
1. In the bowl of a stand mixer fitted with a dough hook, pour in water, yeast and 1 tablespoon of the granulated sugar. Stir and proof 5 minutes.
2. Once mixture looks bubbly and frothy, pour in remaining sugar and salt. Stir on low for 15-20 seconds. In a small bowl, measure buttermilk, oil and egg. Whisk ingredients together until egg is incorporated to other two ingredients.
3. Pour contents into the water and yeast mixture. Stir another 20 seconds in the mixer. Pour 2 cups of flour into mixer and stir on low until incorporated.
4. Sprinkle flour in by 1/4 cup increments until dough cleans the sides and bottom of the bowl. (This takes awhile) Dough should be sticky but not sticky enough to stick to your hands when touched. Once it has reached this stage, turn mixer on and knead for 5 minutes. (Maybe it was my mixer, but this did not work with me. The dough kept on come out of the bowl. So I ended up simply taking the dough out kneading it myself for about 6-7 minutes.)
5. Remove dough from bowl, grease and replace back into same mixing bowl {since it's practically clean anyways.} Cover with plastic wrap and a dish towel. Rise 1-2 hours or until dough has doubled in size.
Filling and Cutting Rolls-
6. In a medium size bowl, stir brown sugar, cinnamon and cornstarch together until combined. Set aside. Punch down dough. Flour a large clean table liberally with flour. Lightly flour dough as well.
7. Roll dough out to be a 20x30 rectangle (Mine was much smaller then this because I couldn't get it this big and didn't have somewhere to roll it out that big. Mine was about 20x15) while moving dough around to ensure it's not sticking to your work surface. If it's a little short or uneven, feel free to cut off the edges to even it all out.
8. Spread softened margarine over dough, being sure to go right to the edges leaving a 1-inch strip untouched on one of the longer sides of dough.
9. Dump brown sugar mixture onto the middle of the dough and spread with your hands, creating an even layer over top of the margarine, still leaving that 1-inch strip of dough untouched. If you have any filling that falls off the sides of the dough, use a bench scraper to replace. Lightly press the sugar mixture into the margarine using a rolling pin.
10. Roll the dough up into a tight log, finishing with the plain dough on the bottom to seal the entire thing together. Cut off the uneven ends to even out the log.
11. Score log every 2 inches and then slice your rolls using those marks. Place into parchment paper lined, margarine greased pans. 12 into a 9x13, 3 remaining into a loaf pan, or 8x8 with the small ends. Cover pans with plastic wrap and dish towels.
12. Let rolls rise another 1-2 hours or until they are touching and have risen almost double. My rolls always spread out more than up, so just be aware that they will most likely spread out more than up. Bake in a preheated 350 degree for 17 minutes, or until tops start to brown. Watch them carefully!!
For the Frosting-
13. While the rolls are baking, whip cream cheese and margarine together. Stir in vanilla, corn syrup and lemon juice. Scrape sides and mix again.
14. Pour in powdered sugar and stir slowly until it starts to incorporate. Then mix on high for 5 minutes or until frosting starts to lighten in color. Scrape sides and mix again briefly.
15. Once rolls have been removed from the oven, frost using half the amount made. Then after they have cooled a few more minutes, frost again with remaining frosting. The first frosting will melt down into the rolls and the second layer should stay put. Serve warm.