Mix sugar and butter together in a large bowl until completely blended. Add banana, vanilla, milk, and eggs. Combine.
Add to the wet ingredients: flour, baking powder, walnuts, and cranberries. Mix until fully incorporated (without over-mixing) and pour batter into a greased loaf pan, muffin pan or mini muffin pan.
Follow times below depending on pan used:(Loaf pan) 1 hour 10 minutes or until toothpick comes out clean or with a normal crumb.(Muffin pan) 27-29 minutes(Mini muffin pan) 16 minutes