Preheat oven to 350° F. Grease and line a 9x5-inch loaf pan with a long strip parchment paper down the middle with overhanging sides.
Prepare the kiwi puree by placing peeled kiwi fruit in a food processor or blender. Blitz until no large chunks remain and you have a puree. Measure out 3/4 cup and set aside. If there’s any remaining puree, use on top of porridge for breakfast or eat right then and there.
In a small bowl whisk together flour, baking powder, and salt.
In a large bowl or bowl of a stand mixer, beat together melted butter and sugar, about 1 minute. Beat in eggs, one at a time, mixing well after each addition. Beat mixture until pale in color, about 2 minutes.
Add 1/2 of the flour mixture and mix until combined. Follow by adding 1/2 the of milk. Repeat with remaining flour and milk and mix just until combined. Using a spatula scrape down sides and mix well. Mix in kiwi puree.
Scrape batter into prepared pan and smooth top. Bake in the middle rack of the oven for 45-50 minutes or until the top is golden brown and a toothpick inserted into the center of the loaf comes out clean.
Let cool 5 minutes before removing loaf from pan. Loosen sides of pan with a knife if needed. Let cool completely on a wire rack before slicing.