Step 1

Preheat oven to 350 degrees.In a large mixing bowl, cream butter and sugar for 4-5 minutes until light and fluffy.  Scrape the sides of the bowl and add the eggs and vanilla. Cream for 1-2 minutes longer.

Step 2

Stir in flour, cream of tartar, baking soda, and salt, just until combined.

Step 3

In a small bowl, stir together sugar and cinnamon.

Step 4

If time allows, wrap the dough and let refrigerate for 20-30 minutes.  Roll into small balls until round and smooth.  Drop into the cinnamon-sugar mixture and coat well. Using a spoon, coat for a second time, ensuring the cookie balls are completely covered.  *To make flatter snickerdoodles, press down in the center of the ball before placing it in the oven. This helps to keep them from puffing up in the middle. *

Step 5

Place on a parchment paper-lined baking sheet. Bake for 9-11 minutes.  Let cool for several minutes on the baking sheet before removing it from the pan.

Step 6

In a large mixing bowl, cream together butter and cream cheese for about 3 minutes. Add powdered sugar and vanilla. Mix until fully incorporated. If you want a thinner frosting, add 1 Tablespoon of milk or cream. Spread on cooled cookies. Sprinkle with cinnamon-sugar.

Step 7

May serve chilled.