Blend the powdered sugar and almond flour together. Beat the egg whites until stiff peaks form, starting with 1 tablespoon of sugar, then gradually adding the rest.

The egg whites should be firm, shiny, and smooth.

Add the blended almond flour and powdered sugar to the egg whites in two parts, mixing gently until the batter is smooth and flows in ribbons (this is called macaronage).

Using a piping bag fitted with a 5/16-inch (8mm) tip, pipe the batter onto a baking sheet to form macarons.

Let the macarons rest at room temperature for 15 minutes, then bake at 285°F (140°C) with convection for 14 minutes. Let them cool on the baking sheet.

Prepare the vanilla cream. In a mixer, whip the mascarpone, then add the heavy cream, powdered sugar, and vanilla extract while mixing. Chill for a few minutes, then transfer to a piping bag to fill the macarons.

Pipe the vanilla cream onto the center of one macaron shell, then sandwich with another. Let the filled macarons rest in the refrigerator overnight.