In a large bowl, cream together shortening, granulated sugar, and brown sugar on medium speed until light and fluffy. Add bananas, vanilla extract, and butter flavoring, mixing until combined. Blend in eggs, one at a time, beating well. Mixture will look a bit curdled.
Add the flour mixture to the egg mixture, half at a time, beating to combine. Fold in chocolatechips by hand. Refrigerate dough for 1 hour.
Drop cookie dough by heaping teaspoons 1-1/2 inches apart on prepared baking sheets. Bake about 12 to 15 minutes, until golden brown. Remove to racks and cool to room temperature.
Store Banana Chocolate Chip Cookies in a covered container up to 1 week