Baking – Ascorbic Acid (Vit C powder) with Baking Soda = Single Acting Baking Powder

Normal double-acting baking powder makes CO2 (thus giving a rising effect) in two ways: when it gets wet, and when it is heated.

Baking soda only makes CO2 when it gets wet.

From Wikipedia:

The acid in a baking powder can be either fast-acting or slow-acting.[6] A fast-acting acid reacts in a wet mixture with baking soda at room temperature, and a slow-acting acid will not react until heated in an oven. Baking powders that contain both fast- and slow-acting acids are double acting; those that contain only one acid are single acting. By providing a second rise in the oven, double-acting baking powders increase the reliability of baked goods by rendering the time elapsed between mixing and baking less critical, and this is the type most widely available to consumers today.

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.