I'm trying out Toba Garrett's glace icing and it calls for 3/8 milk and corn syrup. How much is that? I'm guessing 1/3 cup??? Am I right or does anyone know the right amount. Thanks

3/8 is very close to 1/3. With this icing, it is relatively forgiving. If it is too thin add sugar, too thick some liquid.

3/9 reduces down to 1/3... so 3/8 is just a tad under the 1/3 c

JoAnnB is right thought.. Go with the 1/3 and if you need a little more sugar add some more.