You can use Sweet 'N Low or Fasweet in place of Sugar Twin or increase the Splenda to 1 cup.

Aspartame (Nutrasweet, Equal) is not heat stable but saccharin - which is what Sweet 'N Low and Fasweet is - is heat stable. Check what the is made from since that's another option.

Here's the link to measuring sweeteners if you use the Sweet 'N Low or Fasweet.

Karen