Place one baking sheet on top of the other to insulate the cookies, and place a silicon baking sheet or parchment paper on the top baking sheet.
Mix almond flour and powdered sugar together in a food processor for 3 minutes, until you get a nice, powdery texture. Sift mixture into a large bowl.
Stir one egg white into the ground almond mixture using a flat, rubber spatula. Mix until you get a paste that is consistent in texture. Set aside.
Whisk the remaining two egg whites on high speed in a large mixing bowl until you achieve soft peaks. Set aside.
Pour water, rosewater and granulated sugar into a small pan and place on your stove on high heat with the candy thermometer dipped into the mixture. Allow to boil until it reaches 230°F (110°C), stirring occasionally to prevent burning.
Resume whisking the egg whites on med-high speed and slowly pour the hot sugar syrup into the bowl. Beat for about 10 minutes, or until you end up with a puffy and shiny meringue.
Quickly fold meringue mixture into the almond paste for 30 seconds, then slowly to check the consistency.The resulting mixture would be thick, fluffy and viscous. It will not be watery. It will almost feel and look like marshmallow fluff. DO NOT OVERMIX!
Transfer meringue mixture into a pastry bag.
Pipe mixture onto your lined baking sheet. Create small domes about 1 1/2 inch in diameter, 2 inches apart from each other to allow for spreading while baking.
Rap the baking sheet firmly against the counter, making sure to do it in one swift movement. This helps form the “feet,” or little fluffy edge to the cookies.
Place your oven rack in the top part of your oven and preheat to 300°F (149°C). Allow to preheat for at least half an hour, ideally for the duration of the next step.
Dry the batter at room temperature, uncovered, for 25 minutes. The circles should not stick to your finger when you touch them. If they do, let them dry a little longer.
Place baking sheet into the oven and bake for 12 minutes.
The cookies should be easy to peel off the pan. If not, put return the baking sheet into the oven for 2 more minutes.
The baked cookies have a smooth top, a soft center and a cute little “foot.”