Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a mixing bowl, whisk together the flour, baking soda, cream of tartar, and salt.

In another bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.

Beat in the eggs one at a time, then stir in the vanilla extract.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Fold in the chopped apple gently.

In a small bowl, mix together the granulated sugar and ground cinnamon for the coating.

Using a cookie scoop, form balls of dough and roll them in the cinnamon sugar mixture.

Place the coated dough balls on the prepared baking sheet, spacing them about 2 inches apart.

Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.

Let them cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.