Preheat oven to 350°F or 180°C. Line muffin pan with muffin liners.
Cut 1½ apples with the peel on into small dice and add it to a bowl.
Toss with 1½ teaspoons cinnamon, 1 tablespoon sugar, and 1 tablespoon lemon juice. Set aside to marinate while you make the batter.
To a mixing bowl, add ½ cup milk, ¼ cup sugar, ¼ cup olive oil, 1 tablespoon vanilla extract, and the grated zest of 1 lemon. Whisk until well combined.
Grate the remaining 1½ apples (peel on) with the large holes of a box grater and add them to the bowl with the liquids. Stir with a spoon.
Sift in 2 cups all-purpose flour, 1 tablespoon baking powder, and 1 teaspoon baking soda and stir until combined without overmixing.
Now, stir in the diced marinated apples.
With a spoon, arrange the batter into your prepared muffin pan. Optionally, sprinkle the muffins with a pinch of sugar.
Bake at 350°F or 180°C for about 25 minutes or until a toothpick inserted in the center comes out mostly dry.
Cool down on cooling rack.
