Pre-heat oven to 350*F.
In a large bowl, beat together your butter and sweetener until light and fluffy. Add your egg and extracts and beat once more until combined.
In another bowl, whisk together all of your dry ingredients including; almond flour, coconut flour, arrowroot starch, xanthan gum and salt.
Pour the dry ingredients into the wet and stir well until the dough becomes thick and everything is incorporated together.
Form your dough into a circle and then roll out flat between two sheets of parchment paper to the thickness you want your cookies (they won't change in much in the oven).
Using a linzer cutter or cookie cutters, cut whole cookies (with now center hole) out of half of the dough. (Re-roll scraps when you need to)
Then add the little attachment for the center cut-outs that you prefer and punch out the other half of the cookies. Basically you should have. equal amounts of cookies with cut-outs and solid cookies with no center cut-outs. Continue to re-roll any dough scraps and repeat the process until all of the dough is used up.
Place the sugar cookies on a parchment-lined baking sheet and bake them for 7-8min. The should still be light in colour and will set as more as they cool. Let them cool completely before attempting to fill them.
To fill the cookies, take one solid cookie and one cookie with a center cut-out and top the solid cookie with a small portion of jam. Sandwich the cookies together as you would oreos so you can see the jam peaking through the center. Serve immediately or chill/freeze them for later. Enjoy your Keto Sandwich Sugar Cookies With Jam!