Prepare pate sablee. In a large bowl mix butter with powdered sugar until light and fluffy. Add egg and continue mixing until well combined and creamy. Add almond extract and mix to combine.
In a medium bowl sift flour with ground almonds and salt, whisk and add to butter mixture.
Use a wooden spoon to incorporate the flour mixture into the butter until combined. Make sure you don’t overwork the dough.
Divide the dough in two and wrap each piece of dough with plastic wrap, form into disks and refrigerate for at least 30 minutes.
Roll each piece of dough between two pieces of parchment paper or plastic wrap until it's about 10 in (25cm) in diameter and about 5-6 mm thick.
Use a 9 inch (23-24 cm) ring to cut a circle and use a 4.5 inch (12 cm) diameter bowl or ring to cut the center. Remove the excess dough. Repeat with the other piece of dough and refrigerate the dough rings for about 30 minutes before baking.
Preheat oven to 350F (180C).
Bake for 12-15 minutes or until golden brown. Allow to cool completely.
Prepare the Mascarpone Frosting: In a large bowl mix Mascarpone with powdered sugar and vanilla until combined.
In another bowl mix cream until stiff peaks form. Gradually fold into the Mascarpone mixture. Put frosting in a piping bag with a medium round tip, (9-11mm).
Place one piece of cookie on a serving platter, and fix with with a bit of frosting. Pipe even dollops of frosting on top of the cookie. Top with the other cookie and pipe again with frosting.
Refrigerate until ready to serve, up to 24 hours before serving.
Decorate with fresh berries, flowers , chocolate or macarons. Enjoy!