Use cupcake holders and place in the muffin pan, or grease the pan.
Peel the apples and cut into small 1/4" size chunks.
Add the lemon juice and mix and set aside.
In another bowl, mix the flour, baking powder, baking soda, sugar and ground cinnamon.
In a smaller bowl add eggs, butter and vanilla and mix. Add this mix into dry ingredients bowl.
Mix together and add apples in and stir thoroughly to incorporate.
Take the batter and fill the muffin tin up to the top. This should fill 1 tin of 12 muffins completely. You can use an ice cream scoop to measure out the batter or use a measuring cup.
Place into oven and bake 15-20 minutes until a toothpick comes out clean.
Video
Notes
Note: Make sure to cut the apple pieces into pieces dime size, so they will cook evenly.