Combine pears, water, lemon juice, cinnamon, ginger, and vanilla in a large saucepan. Bring to a boil over high heat. Reduce heat to medium-low and simmer, stirring occasionally, until pears have softened, about 25-30 minutes.
Use an immersion blender to process the pear sauce until smooth. If you prefer a chunky pear sauce, mash with a potato masher. You can also transfer the cooked pear mixture to a food processor or blender to process, just make sure the pear sauce has cooled down.
Once the pear sauce has cooled down, pour into glass or plastic containers. Cover and store in the refrigerator. The pear sauce will keep in the fridge for one week. You can also freeze or can the pear sauce.