Beat almond flour, salt, butter: Place the almond flour, salt, and butter into an electric mixer with a paddle attachment and beat on medium speed for three minutes. The mixture will become coarse and chunky looking.
Add one of the eggs, reserving the other for later, and the almond extract. Mix on low speed until just incorporated.
Sift together the flour, sugar, and baking soda then add to the butter mixture at low speed. Mix until just combined.
Chill the dough: Take the dough and flatten it into a disc and wrap in plastic wrap. Place it in the refrigerator for two hours to chill.
Prep oven, baking sheet, egg: Preheat the oven to 325°F. Line a baking sheet with parchment paper. Place the other egg into a bowl and beat it.
Flatten balls of dough onto cookie sheet: Take pieces of dough and roll them into balls about three-quarters-of-an-inch wide. Place them on the sheet about an inch apart and then press them down slightly with your palm to make a coin shape.
Place a slivered almond onto each cookie and lightly press it into place, then paint the surface of the cookie with some of the beaten egg using a pastry brush or your finger (this will give the cookie a lacquered appearance once it bakes).
Bake at 325°F for 13-15 minutes or until the edges just begin to tan. Cool on the sheet on a wire rack.