Preheat oven to 350°F (175°C). Grease and flour a 9x5-inch loaf pan.
Cream cream cheese and butter together until fluffy.
Beat in sugar and lemon zest until light.
Add eggs one at a time, mixing after each.
In a separate bowl, combine flour, salt, baking powder, and cinnamon.
Alternate adding dry ingredients and milk to the batter, mixing gently.
Fold in diced peaches.
Pour batter into prepared loaf pan and smooth top.
Bake 50–55 minutes, or until toothpick comes out clean.
Cool 10 minutes in pan, then remove and cool completely.
