Preheat oven to 325 degrees. In a large mixing bowl, combine all dry ingredients (flour, baking powder, salt, sugar and lemon zest). Mix well.
In a separate bowl, combine shortening, egg, flavorings, vinegar and lemon juice and whisk well to combine.
Add liquid to dry ingredients and stir until all ingredients are well incorporated. The dough should be dry enough that you can touch it and even almost knead it with your hands.
You can refrigerate it for about a half an hour if desired or if it’s really warm in your kitchen, but you can probably go ahead and roll it out right now if you want.
Prepare two baking sheets by covering with parchment paper or silicone baking mats.
Dust your work surface with a little of your gluten free flour and roll the dough to about 1/4 inch thickness. Cut into desired shapes and transfer cookies to baking sheets.
Depending on the size of the cookies you made, they will bake anywhere from 10-15 minutes. I tend to make sort of large, sand dollar sized cookies and they take 14-15 minutes to bake through until just slightly browned around the edges.
Rotate trays half way through cooking – this means to take the tray on the top rack and swap it with the one on the bottom rack and spin them around so the part of the tray that was in the back of the oven is now in the front.
Once edges are slightly browned, remove from oven and move to cooling rack to cool completely. Decorate or frost as desired. Store in an airtight container. Room temperature is fine.
You can enjoy these as is or make a simple icing of powdered sugar, coloring of your choice (see my tips for this in the video) and a little liquid. I used more lemon juice and a touch of water.