Peel, core, and slice the Granny Smith apples into small chunks. No need to be perfect; the apples will break down as they cook.

In a large saucepan or Dutch oven, combine the apple chunks, cranberries, water, sugar, lemon juice, cinnamon, and a pinch of salt.

Stir to combine, then bring the mixture to a simmer over medium heat. Once it starts simmering, reduce the heat to low and cover the pot.

Let the apples and cranberries cook for 30-40 minutes, stirring occasionally. The apples will soften and break down, and the cranberries will burst open, releasing their tartness into the sauce.

Once the apples are soft and the cranberries have burst, use a potato masher or a spoon to mash the sauce to your desired consistency. For a smoother applesauce, you can use an immersion blender or transfer the mixture to a regular blender (in batches) to puree it.

Taste the applesauce and adjust the sweetness or tartness if needed. Add more sugar for sweetness or a bit more lemon juice for a tangier flavor.

Allow the cranberry applesauce to cool slightly before serving. It can be enjoyed warm or chilled, depending on your preference. Store any leftovers in an airtight container in the refrigerator for up to a week.