These are a difficult project. They take a lot of patience, but if done properly can be mastered.
200 g almond flour
200 g icing sugar
200 g granulated sugar
50 g water
150 g egg whited, divided into 75 and 75, at room temperature
Stack two baking trays on top of each other. Line with parchment paper or a silicon mat.
Process almonds and sugar in food processor. Sift out and large pieces of almond.
Heat water and sugar on the stop. Mix and heat until sugar is dissolved and mixture reaches 245˚F.
While heating begin whisking 75g egg whites in electric mixer on high. When they have stiff peaks either stop mixer.
Turn mixer on low, slowly pour sugar mixture into egg whites.
Continue to whip on high for 5-7 minutes until cooled, glossy and firm.
Mix almond mixture and other 75g egg whites (until just combined).
Fold egg whites into almond meal without deflating. Batter should be thick and flow slowly without over-mixing.
Scoop into piping bag with circular tip (1/2 inch diameter).
Pipe 1 1/2 inch circles onto baking sheet. Hold piping bag about 1 cm above tray, and move tip quickly off the circle when finished piping.
If top doesn’t smooth out, use a finger dipping in water to smooth out top.
Allow shells to harden for 30 minutes, tops should be dry and not glossy.
Preheat oven to 320˚F.
Bake for 15 minutes, rotating halfway through.
Fill with jam, nutella or buttercream icing.