Preheat oven to 350 degrees. Line large cookie sheet with parchment paper.
Combine flour, baking soda, and cream of tarter into a large bowl. Whisk ingredients together and set aside.
Using an electric mixer, beat the butter and sugar, egg and 1 tsp of vanilla extract until creamy.
Slowly add the flour mixture, one cup at a time, stirring to combine after each addition.
Once combined, lightly flour a cutting board and knead the dough until combined
Roll dough out to 1 inch thick
Cut 24 heart cookies
Using the mini heart, cut out a heart into the middle of 12 regular size cookies
Bake the cookies for 15 minutes
Once baked, let cookie cool completely