Pour/spread the mixture evenly onto the baking sheets.
Place in oven and cook until firm and no longer sticky to the touch (3-4 hours in most ovens).
Remove from oven and let cool.
Cut into strips and roll up with parchment paper.
Store in an air-tight container until ready to eat.
If using frozen defrosted berries, the liquid will be thinner. If using fresh berries, you may have to add a couple teaspoons of water to get the mixture smooth enough to spread. The mixture should be pourable but not thin enough to run off the baking sheet.Can be stored in the refrigerator or freezer in an airtight container for up to a week (refrigerator) or two months (freezer).