Preheat oven to 400 degrees F (205 degrees C). Grease muffin tin(s) with cooking spray (PAM, Crisco, et cetera).
In a small bowl, Beat egg with fork. Stir in milk and applesauce until combined.
In a separate bowl, sift flour. Add sugar, baking powder, and salt.
Add egg mixture to flour mixture and stir just until moistened--batter will have lumps. DO NOT OVERMIX.
Gently fold poppy seeds and blueberries into batter.
Fill muffin tins 2/3 full.
Bake 20-25 minutes, or until golden brown. Muffins should have beautiful rounded tops.