Preheat oven to 350 F. Line a baking sheet with parchment paper.

Place sugar in a small bowl. Zest lemons into sugar and work in with clean fingertips until the sugar is fully coated. Let the mixture rest 15 minutes before using.

In a large bowl combine flour, baking powder, salt, xanthan gum (if using). Whisk. Add sugar mixture and whisk again to combine.

In a small bowl mix lemon juice, flavorings, oil and eggs. Whisk to combine.

Add the wet ingredients into the dry and stir. Using clean hands fully combine and then gently add in almonds.

Form into 2 logs on parchment paper lined sheet pans (about 1/2 inch tall, 2 inches wide and 15 inches long).

Bake 10 minutes. Turn oven to 325 F and bake 20 minutes more. Logs will not be brown.  Cool. Cut gently with serrated knife into half-inch wide slices. Be gentle- they tend to crumble at this point.

Stand slices up on baking sheet. Bake at 325 F for 10 minutes. Rotate pan & bake 30 minutes more at 275 F (until golden brown). Cool thoroughly.