For the filling: Heat the raspberry juice concentrate in a small saucepan to a simmer. Add brown rice flour and stir constantly for about a minute until thickened. Set aside to cool.
For the cookies: Preheat oven to 350 degrees. Mix dry cookie ingredients in a bowl. Mix wet cookie ingredients in a separate bowl. Mix wet and dry cookie ingredients together. If the dough seems too wet to roll out, add 1 to 2 tablespoons of baking flour. Roll out onto well floured surface to about 1/8 inch thick. Cut into desired shape with cookie cutter or the rim of a small glass. Place on greased cookie sheet and bake for 8 minutes. Cool on rack.
When the cookies have cooled and the filling is no longer hot (warm to room temperature is ideal), spread filling between two cookies. Let cookies cool and refrigerate. Makes about 20 cookie sandwiches.
