To prepare, preheat your oven to 350 and spray a muffin tin with non-stick spray.
To a large mixing bowl, add your butter, white sugar, and applesauce and whisk them together till smooth. Next, add the vanilla, lemon juice, lemon zest, and eggs and whisk again. While whisking, slowly add your milk to your wet ingredients till everything is well combined.
To the same bowl, add your oats, baking powder and salt and stir together till combined. Add your zucchini and blueberries and fold them into your batter.
Fill each muffin tin full to the top with your oatmeal batter. Bake in the oven for 18-22 minutes, or till the top is fluffy and a toothpick inserted comes out clean.
Stored in an airtight container in the fridge, these last about a week.