Cream butter until fluffy (I usually do this in mixer but the food processor works too). Add eggs, sugar, molasses vanilla extract, spices, baking powder, salt and xanthan gum. Scrape down and mix again.
Add flours and mix, scraping down the bowl once mid mix.
Pour dough onto starched parchment paper, top with a bit of starch and top with more parchment and press to ½ inchish thick.
This dough needs a good chill, I keep it cold and roll out shapes and then pat thin and reroll.
Preheat oven to 350.
Line a couple baking sheets with parchment.
Roll these anywhere between 1/8 of an inch for crisp cookies and ¼ inch for tender crip cookies.
Bake 8-10 mins until just browning at the edges.
Definitely let them cool on the pan a bit before moving to a cooling rack and only reuse cookie sheet once it is completely cool.