Preheat oven to 350° f.
Grease bottom only of a 9 x 5 x 3 inch loaf pan.
Mash bananas in a large bowl.
Add sugar, milk, oil, vanilla, and eggs to the mashed bananas. Stir.
Add Bisquick to above wet ingredients and stir.
Gently fold in chocolate chips or nuts.
Pour banana bread batter into prepared pan.
Bake 50 to 60 minutes until toothpick inserted in center of loaf comes out clean.
Remove from oven and cool in pan on wire rack for 10 minutes.
Gently loosen sides of loaf from pan and cool completely, flat side down, on a wire rack for at least 2 hours until slicing.