Line a 9 x 5-inch loaf pan with parchment paper or grease; set aside.
In a large bowl, beat butter with sugar until fluffy; beat in eggs, 1 at a time, heating well after each. Beat in bananas, vanilla and lemon juice.
In a separate bowl, whisk together flour, baking powder, baking soda and salt. Sitr into butter mixture alternately with milk, making 3 additions of dry ingredients and 2 of milk. Fold in cranberries and nuts. Scrape into prepared pan, smoothing top.
Bake in centre of 350°F oven until cake tester inserted in centre comes out clean, about 1 ¼ hours. Let cool in pan on rack for 5 minutes, Remove from pan and peel off paper; let cool completely. Wrap in plastic wrap; store at room temperature for 24 hours before slicing. (It will be crumbly if you try to cut it before this.).