Baking Help for Sugar cookies

[Guest guest]

I made sugar cookies last year and the recipe was very crumbly. Here is the

recipe any help/ideas.

1/3 margarine or butter

1/3 shortening

1 cup rice flour

1 t. xanthan gum

1 t. unflavored gelatin

1 egg

3/4 c. sugar

1 T milk

2 t. baking powder

1 t. vanilla

1/4 t. salt

1/2 c tapioca flour ( is it the same as tapioca starch flour?)

1/2 c. potato starch flour

mix first two add the rest

cover and freez

I think I used Splenda because my daughter has diabetes (the Splenda half/half.

milk might have been 1%

My kids love baking sugar cookies and decorating them. Thank you for your help.