Preheat the oven to its lowest setting; 170°F is ideal, but no higher than 200°F. Line two baking sheets with parchment paper or silicone baking mats.
In a blender, combine all the ingredients and blend until smooth. For completely smooth fruit leather, strain the puree through a fine-mesh strainer into a bowl, pressing on the solids to extract all the liquid.
Pour the puree onto the lined baking sheets, make a loose rectangular outline around the pan with it, and then fill it in. Tilt the pan to form a thin layer (but not so thin that it’s transparent—if that happens, make your fruit leather smaller) that is as even as possible. Use a silicone spatula to make any final adjustments to the layer.
Bake until the roll-ups are only very slightly tacky to the touch but peel fairly easily from the parchment, anywhere from 2 to 5 hours, depending on the type of fruit you use and its moisture content.
Cut the roll-ups right through the parchment into strips (any size you like) and test one to see if it pulls off the paper easily. If it’s still a little tacky, return them to the turned-off oven (tape the handle to the door to remind yourself not to turn it on!) and leave for up to 5 hours more, or simply leave them to dry on the counter.
Roll up the strips, tie them with kitchen string, and store in a sealed bag at room temperature for up to 2 weeks, in the refrigerator for up to 1 month, or in the freezer for up to 1 year.