In a pot, add the chopped rhubarb. Then add a little water to cover the bottom.
Cook covered on medium until the rhubarb is softened. Drain most of the liquid off.
Using a hand blender, blend until smooth. Be careful not to splash as the rhubarb is hot.
Once the rhubarb is pureed. Add the applesauce and sugar to taste and mix well. The mixture should be slightly tart, as it will sweetened once dried.
Spoon the rhubarb mixture onto a dehydrator tray lined with a fruit leather sheet or parchment paper.
Smooth the mixture to make the edges thicker than the middle. This will ensure more even drying.
Dry at 135 degrees to 145 degrees for 4-6 hours. Or until the mixture is dry and can easily be peeled off the tray liner.
Cut into strips and roll. Store in an airtight container for up to a month at room temperature. For longer storage store in the freezer up to 1 year in a tightly sealed container.
You can also dry fruit leather in the oven if you don't have a dehydrator. To dry your fruit leather in the oven, set the oven to the lowest temperature.Line a cookie sheet with parchment paper, and spread with puree.Dry at the lowest temperature for 4-6 hours or until fully dried.