To a large bowl combine your applesauce, discard, butter, sugar, eggs and vanilla. I like using a whisk and whip these ingredients together by hand until smooth!
Place a sieve on top of your wet mixture bowl and add the remaining ingredients to it minus the blueberries. Sift your dry ingredients into the wet. Using the whisk, softly mix the dry ingredients on top and then bring the whisk down to the bottom to continue a good mix. Do not over mix here, just keep mixing until everything is combined and there are no dry spots!
Cover the bowl and place in the fridge overnight or for at least 4 hours to cool the batter. This will help with fluffiness and moisture content!
When ready to bake, preheat your oven to 350 degrees.
Add in your blueberries and fold into batter gently with a spatula.
Take about 1/4 cup of batter and pour into your muffin tin, either greased or lined with muffin cups. I like to take my muffin tin that holds 12 muffins and only use six of the muffin molds at a time, spacing out my muffins. This helps with heat and a better cooked, fluffy muffin. But feel free to cook 12 at a time!
Bake for 20-25 minutes or until passes the knife test.
Enjoy after cooled down and store in the fridge for 7-10 days.
Reheat and spread butter over them to enjoy to their fullest!