Preheat the oven to 350°F. Line two large cookie sheets with parchment paper and set aside.
Add the flour, almond flour, salt, and baking soda in a medium mixing bowl and whisk together.
In a separate large bowl, use an electric hand mixer to cream together the butter and sugar until the mixture is fluffy.
Add the 2 large eggs, one at a time and extract; mix until the eggs have been incorporated.
Pour in the dry ingredients and continue mixing until a thick and slightly sticky dough is formed.
Use a cookie scoop to scoop out 1 1/2 tablespoons of dough. Dust your hands with flour and roll the dough with your hands into tight balls.
Place the dough balls on a prepared cookie sheet about two inches apart (about 12 cookies per cookie sheet). Lightly press the dough balls with your fingers or the back of a spatula to flatten them out slightly.
Use a pastry brush to coat the top and edges of the cookie dough balls with the beaten egg, then press three almond slices on top of each cookie.
Bake one batch at a time in the preheated oven for 13-15 minutes, or until the cookies are a light golden color.
Allow the cookies to rest on the cookie sheet for 5 minutes, then transfer them to a cooling rack.
Serve at room temperature.
Notes
The cookies may look a little underdone, but they will continue baking as they rest on the cooling rack. You want to make sure you don’t over-bake the cookies or they won’t have a soft texture and the tops will be too dark.
I used a 1 1/2 tablespoon cookie scoop. Please note that if you use a different-sized scoop the number of cookies you have may be different than the recipe says.
Dust your hands with flour before rolling the dough as the dough will be slightly sticky.