Place the dark chocolate chips in a large bowl.

Warm the cream in a small saucepan over medium heat until it just starts to boil.

Stir it into the chocolate without creating bubbles.

Let sit for 1 minute. Add the butter and stir until smooth.

Chill in the refrigerator until thickened but still spreadable, about 30 minutes.

Special equipment

You will need a pastry bag fitted with a 1/2-inch tip. If you don’t have one, you can either spoon round dollops of batter onto the baking sheet or make a pastry bag by snipping off one corner of a large resealable plastic freezer bag.

Preheat oven to 350°F.

Line 2 large baking sheets with parchment paper.

Place the powdered sugar, almond flour, cocoa powder, and salt in a food processor fitted with a blade attachment and pulse several times. Process until fine and combined, about 30 seconds.

Sift through a flour sifter into a large bowl; set aside.

Place the 3 egg whites in the clean bowl of a stand mixer fitted with a whisk attachment. Beat on medium speed until opaque and foamy, about 30 seconds. Now add a pinch of cream of tartar, increase the speed to medium high, continue to beat until the egg whites are white in color and hold the line of the whisk, about 1 minute.

Continue to beat, slowly adding the granulated sugar, until the sugar is combined, the peaks are stiff, and the whites are shiny, about 1 minute more. Do not over whip. Transfer the meringue to a large bowl.

Take a rubber spatula, and now gently fold the dry mixture with the egg whites in four different scoops until the dry ingredients are just combined.

Now you will need to spoon half of batter into pastry bag fitted with 1/2-inch plain round tip. Pipe batter onto each prepared sheet in 12 walnut-size mounds, spacing mounds apart because cookies will spread slightly.

Bake cookies, 1 sheet at a time, until firm to touch in center and dry and cracked on top, about 7 minutes pull the pan put and then rotate and bake for another 7 minutes.

Arrange 1 macaroon, flat side up, on work surface. Drop 1 scant tablespoon filling onto cookie.

Top with second macaron, flat side down.

Press lightly to adhere, making sandwich.

Repeat with remaining macarons and filling. Arrange macarons on platter.

Cover; chill at least 2 hours and up to 1 day.

Serve cold.