In a large mixing bowl, combine eggs, sugar oil and vanilla.
2 eggs, ½ cup sugar, ¼ cup oil, 1 teaspoon vanilla
Mix in mashed bananas and grated apples.
¾ cup mashed bananas, ½ cup grated apple
Add flour, and sprinkle cinnamon, baking powder and salt on top of the flour.
2 cups flour, 2 teaspoons baking powder, 1 teaspoon cinnamon, ½ teaspoon salt
Begin mixing the dry ingredients together on top of the wet ingredients and then mix everything together.
Scoop batter and place into lightly greased or paper-lined muffin tins.
Bake in preheated 375°F oven for 15-17 minutes until cooked through.
Allow muffins to cool 3-5 minutes in pan and then remove from pan and continue cooling on a cooling rack.
Notes
Use fresh baking powder: Baking powder can lose its effectiveness over time. If it's old, your muffins may not rise properly.
Grate the apple: Use the large holes of a box grater. There's no need to squeeze the moisture from the grated apple before adding it to the batter.
Fully preheat your oven: I use a separate oven thermometer to make certain my oven has reached the proper temperature. My preheat light often turns off before the oven has reached full temperature, so I always give it extra time.
Don't overmix the batter: Stir just until everything is combined. Overmixing can cause tough muffins.
Prepare your muffin tin: Use paper liners or spray the muffin cups with a nonstick spray.
Use an ice cream scoop: This helps make evenly sized muffins and makes it easy to portion the batter into the muffin tin.