Unsweetened applesauce is available in the grocery aisle where you can find canned fruits, puddings etc. Name brand or store brand doesn’t really matter. But if buying it from the store I prefer buying organic because apples is one of the fruits listed in the “dirty dozen”, the fruits/vegetables which is recommended to be consumed organic. Also avoid getting the bottled ones because it’s really big and however careful you be to use dry spoon it tends to go bad with fungus growth. So I prefer getting the ones in plastic cups. Each cup has exactly 1/2 cup of applesauce which you would most probably use it all in the recipe.