More Flour - Add 1 ounce of flour for a thicker, puffier cookie.  2. Butter Temperature - If your butter is too warm, your snickerdoodles may spread more than usual. You can also chill your snickerdoodles for 60 minutes for thicker cookies.  3. Oven Temperature - If your oven is not calibrated, it might be cooler than what your dial is saying. Try increasing your temperature by 25 degrees to see if that helps set your snickerdoodles before they spread too far.