Preheat oven to 350°F. Grease baking sheet and set aside.
Cream shortening and brown sugar in large bowl at medium speed until well blended, then beat in egg.
Add one cup mashed banana and mix until creamy.
In a separate bowl, mix together oats, flour, salt, cinnamon, baking soda and nutmeg, then stir into creamed mixture. Fold in chocolate chips.
Using a cookie scoop , drop spoonfuls of cookie dough onto prepared baking sheet (if you don't have a cookie scoop, just use a medium-sized spoon to drop cookie dough onto pan. This cookie dough will be too sticky to roll into balls).
Place cookies 2 inches apart on baking sheet.
Bake for 15-17 minutes, then remove from oven and let cool 1-2 minutes on baking sheet, then remove to a cooling rack.
Notes
To make these chewy banana oatmeal cookies healthier you can:
Switch out milk chocolate chips for dark chocolate chips, mini chocolate chips or sugar free chocolate chips.
Use coconut flour, oat flour or whole wheat flour, in place of all purpose flour.
Use honey, coconut sugar or other natural sweeteners in place of the sugar
Use apple sauce or coconut oil in place of shortening or butter