Baking – Optimal egg size

If they're tangier than you'd like that would be due to the acidity of the cream of tartar. While most recipes for Snickerdoodles do in fact us cream of tartar and baking soda for a homemade form of baking powder (most likely due to the fact that snickerdoodles are fairly "old"-style cookie), a few I looked at are using baking powder and no cream of tartar.

Here are a few things to know and a suggestion:

Acidic doughs do not spread easily and do not brown easily. Using the combination of cream of tartar in the 2:1 ratio w/ baking soda for leavening not only causes them to puff but with the higher acidic ratio it is also likely to help in keeping them more "cakey" and prevent them from browning as much.

You could try cutting back the cream of tartar slightly and seeing if that helps (possible drawback could be the soda making a more pronounced bitter soapy taste if there isn't enough acidity).

Or

Replace the cream of tartar and baking soda with baking powder. Baking powder by volume isn't as powerful as baking soda because of the fact it contains soda, two dry acids, and cornstarch. 1 teaspoon of baking powder will leaven 1 cup of flour (vs. 1/4 teaspoon of baking soda to leaven a cup of flour). If your recipe calls for 2 cups of flour then use 2 teaspoons of baking powder and cut out the cream of tartar and baking soda.

If you want soft and moist, you need egg yolks. Their emulsifier and fat content makes dough pliable, soft and smooth, and retains moisture.

Egg whites dry out a dough. This is sometimes desirable, e.g. in pate a choux. Eclairs made with whole eggs often have wet planes in the middle, resulting in an underbaked impression. If you remove some yolks from the dough and use a mixture of whole eggs and egg whites, you get a firmer, drier dough. But in many cases, people want softer, moister end products, and in such cases, recipes which increase the ratio of egg yolks to egg whites (by using more yolks than whole eggs, or yolks only) will give you a better result.