Preheat the oven to 350° F. Line a loaf tin with parchment.
Measure all ingredients into a mixing bowl and beat with a stand or hand mixer for about two minutes, until well-blended. Mix in ½ cup mini semi-sweet chocolate chips, if desired. Spoon the mixture into the prepared tin and level the surface.
Bake in the oven for about one hour, until well-risen and golden brown. a fine skewer inserted into the center should come out clean. Leave the tin to cool for a few minutes, then turn out onto a cooling rack before slicing and serving.