Gather ingredients.
Pre-heat oven to 350°F.
Zest the lemon and set aside for later.
in a small pot, cream together the butter and sugar on medium heat until combined.
Add applesauce and remaining wet ingredients to pot until fully combined.
Add lemon zest. Mix well.
Sift flour and baking powder. Mix until combined.
Add wet mixture to dry ingredients. Mix well.
Add blueberries, fold in until combined.
Pour into a lightly greased 9x5" loaf pan.
Combine sugar and cinnamon, sprinkle over top.
Bake at 350°F for 60 minutes or until an inserted toothpick comes out clean. Cool for 10 minutes. Remove from loaf pan and let cool completely on a wire rack.
Enjoy!