1. (Parent/Child) Peel and core 2 Fuji and 2 Golden Delicious apples. Using a serrated plastic knife, chop apples and place in a saucepan.
2. (Parent/Child) Stir in 1/4 cup water and 2 tablespoons butter. Cook, covered, over medium heat, stirring occasionally, until soft, about 30 minutes. Let cool.
3. (Child) Mash apple mixture with a potato masher until smooth. Store in an airtight container in the refrigerator for up to 10 days.