In a food processor add the whole almonds and icing sugar. Pulse till everything is well ground and combined. Make sure that you don't blend and only pulse.
Sift this mixture once into a bowl. there will be about 1/2 tablespoon worth of ground mixture remaining in the sieve, discard it. Set aside.
In a large bowl that is very clean and without grease (ensure that the beating attachments of your stand mixer/hand mixer are also clean and grease-free). Add the egg whites and salt. Start whipping at a slow speed.
Once the egg whites start foaming up, add the vinegar.
When bubbles start forming, slowly add in the caster sugar in small additions.
Once all the caster sugar is added, increase the speed and whip, add the vanilla and keep whipping till you reach stiff peaks. (this can take anywhere between 7-10 minutes)
After you reach stiff peaks, add the sifted almond and sugar mixture in three stages, folding gently. Keep folding till the batter is flowing in ribbons from your spatula and you can make a figure 8.
Transfer this mixture into a piping bag and cut a hole about 1/2-inch in diameter. Pipe little mounds into prepared and lined baking sheets. Leave some space between the macarons.
Tap your baking sheet against the counter about 5-6 times to remove air bubbles.
Let your macarons dry for about 15-45 minutes or till it forms a light skin on the surface and it’s top is matte. Meanwhile, preheat your oven to 150 C
Bake your macarons for about 15-16 minutes or until set.
Once baked, let your macarons cool on the baking sheet before removing.
Make the frosting:
Melt your white chocolate and set it aside to cool to room temperature.
In a separate bowl, add the cream cheese and whip until light and fluffy (using a hand held beater/blender). Add the sifted icing sugar and vanilla and blend for 3 minutes, till it is incorporated. Pour the room temperature white chocolate and beat until combined.
Assemble the cookies:
Pair up the cookies according to sizes. Pipe a generous amount of frosting on one cookie and use its pair to sandwich them together.
Repeat for all cookies. Refrigerate them for 24 hours for best flavour and texture.