Preheat oven to 375°F and line baking sheets with parchment paper.
In a large bowl, whisk together the flour, baking soda, and cream of tartar. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter, oil, granulated sugar, and confectioners' sugar on medium-high speed until light and fluffy, scraping down the sides of the bowl as needed.
Reduce the mixer speed to medium and add the eggs, one at a time, mixing just until combined.
Add the vanilla, lemon extract, yellow food coloring, and optional lemon zest, mixing until fully incorporated.
Reduce the mixer speed to low and add the flour mixture in three additions, scraping down the sides of the bowl as needed. Mix just until combined.
Using a 2-tablespoon cookie scoop, drop the dough onto the prepared baking sheets, spacing the cookies about 2 inches apart.
Bake for 8 to 10 minutes, or until the edges are just beginning to turn golden.
Let the cookies cool completely on the baking sheet before serving or frosting.