For the Frangipane
1-In a small bowl, whisk together the: In a small bowl, whisk together the melted butter, sugar, egg yolk, vanilla and almond extract until well combined.
2-Then fold in the ground almonds, flour: Then fold in the ground almonds, flour and pinch of salt. Set aside.

For the Almond Cookies
3-Preheat the oven to 350 degrees F: Preheat the oven to 350 degrees F (175 degrees C). Line two baking sheets with parchment paper.
4-In a medium bowl, whisk the flour,: In a medium bowl, whisk the flour, baking powder, baking soda, and salt together. Then set aside the flour mixture.
5-In a large bowl, cream the butter,: In a large bowl, cream the butter, brown sugar and granulated sugar together with an electric hand mixer on high speed until fluffy, about 2 minutes. (You can also use the bowl of a stand mixer fit with a paddle attachment.)
6-Add in the egg yolks, vanilla and: Add in the egg yolks, vanilla and almond extract and mix together on medium speed until pale in color and fluffy. (Scrape the sides of the bowl as necessary.)
7-Add the flour mixture and ground almonds: Add the flour mixture and ground almonds to the wet ingredients and mix on low speed just until combined.
8-Scoop the cookie dough with a large,: Scoop the cookie dough with a large, 2 tablespoon capacity cookie scoop into 18 portions. (I slightly of overfill my scoop.) Roll each into a ball and use a 1/2 tbsp to make a slight indent in the dough. Add 1/2 tbsp of frangipane to the center of the dough and slightly flatten it out. Top with sliced almonds.
9-Bake 6 cookies at a time, spaced: Bake 6 cookies at a time, spaced 2 inches apart on a prepared baking sheet. Bake for 12-13 1/2 minutes until they are a light golden brown. When the cookies are straight out of the oven, scoot a large circular cookie cutter around them to give them a perfect circular shape. (They will spread while they bake, so scooting a cookie cutter around them is imperative to get the right shape and thickness.)
10-After baking, let the cookies cool on: After baking, let the cookies cool on the cookie sheet for five minutes then transfer them to a wire rack to completely cool. Once cooled, dust each cookie with powdered sugar, then serve!