• Preheat your oven to 180°C (350°F) and line two large baking sheets with parchment paper or silicone mats.

Make the Almond Filling (Frangipane):

• To make the almond cream, add the room temperature butter, salt, and sugar into a large mixing bowl and mix with an electric hand mixer until creamy and smooth.
• Next, add the eggs and mix until well combined.
• Incorporate the almond flour and all-purpose flour, mixing until the mixture is smooth and homogeneous, then transfer the cream to a piping bag with a small slit cut in the tip.

Make the cookie dough

• For the cookie dough, mix the room temperature butter, brown sugar, granulated sugar, vanilla extract, and kosher salt in a large bowl until smooth.
• Add the egg and egg yolk and mix until well combined.
• Gradually add the flour and baking powder, mixing until just combined to ensure the cookies stay moist and tender rather than dry.
• Scoop the dough into 18 balls using a 2-tablespoon cookie scoop and place them on parchment-lined baking sheets before rolling each one smooth by hand.
• Create an indent in each ball using a spoon dipped in flour to prevent sticking.
• Pipe the almond cream into the centers without overfilling. Lightly press sliced almonds onto the cream and bake at 180°C (350°F) for 10-12 minutes.
• For perfectly round circles, gently swirl a cup or biscuit cutter around the cookies while they are still warm, then finish with a dusting of powdered sugar once they have cooled slightly.