I don't have the rest of this post yet cause I'm not a pie maker but this was posted on a GFCF list as a filling for pop tarts. The egg is so the filling doesn't soak through into the pastry. If you have already made these please leave a comment. I don't like to post things until I've made them.
Cinnamon Streusel Filling for myo "pop tarts"
1/2 c brown sugar
1 to 1 1/2 t cinnamon, to taste
4 t flour
1 large egg, to brush on pastry before filling (we used 1/4 c sweet
potato or carrot puree)