• Measure all ingredients. Sift the almond meal and powdered sugar.
• Place egg whites in a bowl, whisk the egg whites on a medium speed until foamy.
• Slowly add in the caster sugar.
• Continue to beat until the egg whites are glossy and have stiff peaks. This may take a while.
• Add in the blue colouring and whisk until the colour is incorporated.
• Sift the almond meal and powdered sugar into the egg white.
• Slowly fold the dry ingredients into the meringue, until the batter flows of the spatula like lava and can form a figure 8 a few times without breaking.
• Fill into a piping bag fitted with a round tip. Pipe 1.5 inch (3.5cm) rounds onto baking paper or silicone mat.
• Set aside to rest for 15-60 minutes, until a skin has formed on the macarons. Test by touching them with your finger, no batter should stick.
• Heat oven to 150c/300F.
• Place in the oven for 20 minutes. If the oven has hot spots, it is best to flip the pan every 5 minutes while baking.
• Remove the macarons if they no longer move when pushed on their feet.
• Set aside to cool completely.

Cookie Dough Buttercream filling

• Place butter in a bowl with brown sugar and powdered sugar. Beat well.
• Add in flour, vanilla, milk and beat until combined.
• Add in the chocolate chips and mix gently until it's dispersed through the buttercream.
• Place into a piping bag.

Assembly

• Match each macaron shell with another shell of a similar size and shape.
• Pipe a mound of buttercream into the centre of one side of each macaron shell. Top with the other shell.