Preheat oven to 350 degrees F (180 degrees C).

Mix shortening and brown sugar, beating well. Add eggs, banana and vanilla. Combine well.

Sift together flour, baking powder, baking soda, and salt. Add to creamed mixture; mix just until combined and flour is incorporated. Gently stir in chocolate chips.

Drop dough by rounded tablespoonfuls, 2 inches apart onto greased cookie sheets. Bake for 10-12 minutes. After letting the cookies rest for a few minutes, remove to paper towels to cool.