Sky blue French macarons with French buttercream

Sift the almond flour with the powdered sugar into a food processor and whizz about 30 seconds, pulsing occasionally; sift back in and whizz again, three times in all, for as fine a powder as possible.

Measure 100 grams of egg white into a stand mixer with the whisk, reserving the yolks.

Add the cream of tartar and whip about one minute until frothy, then very slowly sprinkle in the granulated sugar.

Add the vanilla and raspberry extracts and a few drops of very strong food colouring.

Whip to stiff peaks: the mixer can be turned upside down and the peak does not flop over.

Macaronage: sift a third of the almond flour and powdered sugar mixture into the meringue and gently fold with a long rubber spatula until smooth.

Sift in the remaining dry mixture and keep folding to a smooth goopy batter a little thicker than pancake batter, which forms a figure of eight when it drips off the spatula.

Pipe round dollops onto a parchment lined baking sheet.

Whack the tray thoroughly against the table to release bubbles and flatten the tops, helping them along with a pinky finger.

Let sit uncovered at room temperature for 45 minutes until hardened shells form.

Bake at 300 degrees Fahrenheit for about 12 minutes, rotating once halfway, then cool completely on the baking sheet.

For the buttercream, put the granulated sugar and water in a medium saucepan over medium heat.

Beat five egg yolks in a stand mixer on medium speed until about doubled in volume, while the sugar mixture comes up to 240 degrees Fahrenheit, the softball stage.

Very slowly stream the hot syrup into the running mixer so it does not scramble the yolks.

Once cooled to room temperature, add the unsalted butter one little piece at a time.

Add the raspberry and vanilla extracts and beat in food colouring to match the shells.

Pipe a small circle of the creme au beurre onto the flat side of a cookie and sandwich it with a matching cookie.