Preheat the
oven to 375°F/190°C/gas 5. Butter three cookie
sheets.
Sift the
flour, baking soda, and salt into a medium bowl.
Beat the butter and both sugars in a large bowl
with an electric mixer at high speed until
creamy.
Add the
vanilla and eggs, beating until just blended.
Mix in the banana and dry ingredients, followed
by the chocolate and banana chips.
Drop
teaspoons of the dough 1 inch (2.5 cm) apart
onto the prepared cookie sheets.
Bake, one
sheet at a time, for 15-20 minutes, or until
just golden. Cool on the sheets until the
cookies firm slightly. Transfer to racks to
finish cooling.