Apple Cookies

Preheat the oven to 350°F. Finely dice the apple into very small pieces (about 3/8-inch wide; the smaller the better*).

In a medium bowl, whisk the all-purpose flour, cream of tartar, baking soda, and kosher salt .

In the bowl of a stand mixer fitted with the paddle attachment, beat the room temperature butter and sugar until light and creamy, about 2 minutes. Scrape down the sides of the bowl with a spatula. Add the egg and vanilla extract and beat until combined, about 1 minute.

Turn off the mixer and add the dry ingredients. Then mix on low until just combined. Add the chopped apples and mix for about 5 seconds until combined.

Roll the cookie dough into 20 balls, using about 2 tablespoons of dough per cookie (a cookie dough scoop is helpful).

In a small bowl, combine the sugar and cinnamon. Roll each of the dough balls into the cinnamon sugar mixture until generously coated.

Place the dough balls onto two non-stick cookie sheets (we recommend these non-stick cookie sheets for the most even bake**). Bake for 12 to 14 minutes or until they are puffed and the edges are set, reversing the trays in the oven at 7 minutes. Keep in mind the cookies will set after they cool.

Remove the baking sheet from the oven and let the cookies cool on the sheet for 5 minutes. Transfer to a wire cooling rack and cool completely. Important: Store these cookies refrigerated in a sealed container with parchment between the layers for up to 2 weeks; bring to room temperature before serving.