1. Heat apples, 1/2 cup water, and cinnamon in a medium pot over medium-high. Bring to a simmer, then cover, reduce heat to low, and cook until apples are tender, 25 to 30 minutes. Add raspberries; cook, stirring, until juicy, about 5 minutes. Remove from heat; sprinkle with chia seeds. Let cool slightly, then mash. (If too thick, add water, 1 tablespoon at a time.) Applesauce can be refrigerated in an airtight container up to 2 weeks.