To make macaron shells, line 2 baking sheets with parchment paper.
To prepare dry ingredients, sift together almond flour and powdered sugar twice.
To make the meringue, in a clean mixing bowl with whisk attachment, whip the egg whites at speed 2 until foamy. Add cream of tartar and continue to mix on medium speed.
Start adding sugar one tablespoon at a time, beating for 30 second between each addition. Increase the speed to 4 (medium low) and beat until hard peaks form. This takes 8-10 minutes, but this method makes the most stable meringue.
Add peppermint extract and green food coloring. Continue to beat for a minute or two at speed 4. The meringue should be balled up in the middle of the whisk, and you should see sharp ribs and pointy end. (Watch this meringue video for more information.)
To mix the batter (macaronage): sift the almond flour mixture over the beaten egg whites once again.
Very gently fold the mixture, running the spatula clockwise from the bottom, up around the sides and cut the batter in half. The batter will look very thick at first, but it will get thinner as you fold. Be careful not to over mix it though. Every so often test the batter to see if it reached the right consistency. To test the batter, drop a small amount of the batter and count to ten. If the edges of the ribbon are dissolved within ten seconds, then the batter is ready. I repeat, do NOT mix again. If you still see edges, fold the batter couple more times and test again. (TIP: Making french macarons is all about the technique. This is the most crucial step of all. Let me try to describe the folding motion as best as I can: run the spatula clockwise from the bottom, up around the sides and cut the batter in half. If you’re beginner macaron-baker, I suggest to count every fold. It takes roughly about 50 folds to reach the proper consistency. After 50 folds, start testing the batter, and continue testing after every couple folds.)
To pipe the macarons
, transfer the batter into a pastry bag with a round tip. (I use this Wilton 2A round tip
Pipe out 1.5-inch rounds about an inch apart on prepared baking sheets.
Tap the baking sheets firmly on the counter a few times to get rid of any air bubbles. If you don’t release the air bubbles, they will expand during baking and crack the beautiful macarons shells. And who wants cracked macarons, right?
Let the macarons rest and dry for 15-30 minutes. On a humid day, it might take an hour or so. To see if it’s ready to be baked, lightly touch it. If the batter doesn’t stick to your finger, then it’s ready.
To bake, preheat the oven to 300°F (150°C).
Place one baking sheet with macarons on the middle rack. And place an empty baking sheet on top rack to shield the heat from above and to prevent excess browning.
Bake the macarons one sheet at a time for about 18-20 minutes. It’ll take longer for larger macarons. To test for doneness, touch a macaron lightly and try to move it. If it slides and wobbles, bake a minute or so longer. The cooked macarons should be firm to touch and the base shouldn’t move.
Cool the macarons on the sheet for 10-15 minutes, and then transfer onto a wire rack to cool completely.
To make the filling, bring heavy cream to a simmer, not a boil. (If you're making filling #2, heat the cream and Baileys together.)
Pour the hot cream over the white chocolate chips and let stand for 2 minutes. Then mix until smooth with a rubber spatula.
Using an immersion blender
, blend the mixture until silky smooth, which means the mixture is emulsified. Cover with a plastic wrap, making sure it touches the surface of the ganache. Chill the ganache in the fridge until nice and thick, about 1 hour.
To assemble macarons, transfer the ganache into a pastry bag with round tip. Pair the macaron shells by size and pipe a dollop of ganache on half of the macarons shells. Place the other shell on top and press lightly so the filling is spread till the edges.
Store the filled macarons in an airtight container in the fridge for at least 24 hours to mature. Then bring them out about 30 minutes before serving. These macarons with white chocolate ganache also freeze beautifully. (Read more about maturing, storing and freezing in the post above.)