Preheat oven to 350*F
Prepare chia egg by mixing ground chia seeds and water and allow to stand for 2-3 mins until thickened.
In a mixer with paddle attachment, beat butter and sugar until creamy.
Add chia mixture and vanilla and continue to mix until well combined.
In another bowl, mix flour and baking powder, then gradually add to wet ingredients. Mix until completely combined.
Between two layers of parchment, roll out portions of dough to be cut out.
Transfer cut dough onto cookie sheets lined with parchment.
Bake for 10-12 mins. Allow to cool before decorating!
Drain the liquid of one can of chickpeas into a mixer with the whisk attachment.
Add 4 tbsp vanilla extract.
Whisk for 10-15 mins. Mixture should quadruple in volume and be white and frothy.
Turn mixer to low and gradually add all the icing sugar.
Once combined turn mixer back up on high until a stiff consistency is reached.
For outline consistency: Thin 1C of Royal icing with 1/2 tsp of water. Mixture should resemble toothpaste! (Be sure to color your icing first before thinning out!)
For flood consistency: Thin 1C of Royal icing with 1-2 tsp of water. Mixture should resemble honey! (Be sure to color your icing before thinning out!)
For the Royal icing: I know it sounds like a lot, but you have to use the entire volume of the chickpea in order to yield the proper proportions for icing that will harden. Leftover icing can be refrigerated for up to 1 month or frozen for up to 3 months.