Macarons can be kept for 4 to 7 days in the refrigerator.
Cover two baking trays with baking paper.
Prepare your macaron mat (optional)
Sift the powdered sugar and the almond flour
Put the egg whites and sugar in a heat-resistant bowl.
Bring a pan of water to the boil and hang the bowl with the egg whites above the water.
With the whisk, mix the egg whites with the sugar until the latter is completely dissolved and the mixture is frothy.
Remove the bowl from above the pan and take the mixer (or pour everything into the bowl of your food processor).
Mix at high speed until peaks occur (stop immediately because you do not want to beat).
Spoon the powdered sugar / almond flour onto the egg whites and mix them gently with a spatula. Check whether your batter is ready by making 8 figures above the batter with your spatula. If these remain intact then the batter is ready for use. Then you check with a teaspoon on a piece of baking paper whether the batter flows slightly. That is the moment that you put the batter in the piping bag.
Place your macaron mat on the baking paper and spray the batter into the mold. When you have filled all the molds, beat the baking sheet a few times on your surface, so that all the air can be released. If you do not have a macaron mat, you can spray circles on the baking paper yourself.
Let the macaron dry in the air for about 30 to 40 minutes, the top should be dry.
Meanwhile, preheat the oven to 160 degrees Celsius.
Bake the macarons in the oven for 4 minutes and turn the baking tray 180 degrees. Bake again for 4 minutes. Do this 2 more times (so 16 minutes until you see if the macarons are ready (they are darker and have a border at the bottom), otherwise you bake another 4 minutes.
Repeat for all macarons baking trays.
Allow the macarons to cool further.
Mix the butter and powdered sugar with a mixer until it is light.
Then mix in the baileys, spoon by spoon, while you keep mixing.
Put the baileys filling in a piping bag
Grab a macaron shell and with the piping bag you pipe the Baileys buttercream filling on the shell.
Place a shell on the top.
If you like it, sprinkle the top with silver powder