Combine 1 cup sugar and two cups water in a 9×13 baking dish. Heat in a 400F oven until dissolved (about 15 min). Then set aside.
Add flour, baking powder & salt to a large bowl and stir to combine. Cut in butter or shortening until it resembles a coarse meal. Add milk and stir with a fork until moistened.
Turn dough out onto a flour covered-board and knead gently 20 times. Roll dough into a 10×12 rectangle.
In a bowl, combine strawberry, rhubarb, cinnamon and 1/3 cup of sugar. Spread evenly on top of dough.
Dot with 1 tbsp of butter then roll the dough into a log with the strawberries and rhubarb inside. Cut the log into 10-12 even pieces.
Place slices in 9×13 pan with sugar mixture and bake at 450F for 25 minutes, then at 390F for 20 minutes.
Serve it warm with whipped cream for the ultimate roly poly experience. I was literally licking my plate. It’s that good!