Line two baking sheets with parchment paper or silicone baking mats and set aside.

Sift almond flour, powdered sugar, and freeze dried raspberry powder into a mixing bowl using a fine mesh sieve. Repeat once more to ensure that all of the ingredients are evenly combined, discarding any larger pieces that do not pass through the mesh sieve. Place aside.

In a large mixing bowl, whisk the egg whites until frothy, about 1 minute, then gradually add the granulated sugar, about 1 tablespoon every 20 seconds or so. Increase the speed to medium-high and keep beating until stiff peaks form.

Using a spatula, fold the sifted almond mixture into the egg whites until the batter has the consistency of lava and drizzles off a spatula in a thick ribbon.

Fill a piping bag fitted with a large round tip or a ziploc bag with one corner cut off with the macaron batter. Pipe the macaron batter in 12-inch circles onto baking sheets lined with a silpat mat or parchment paper. Allow the macarons to rest for 30-60 minutes, or until the tops are dry enough to touch. If the day is humid, it may take even longer.

Preheat the oven to 300°F. Bake for 16-18 minutes, one sheet of macaron shells at a time. Allow the macaron shells to cool completely on the baking sheet before attempting to remove them from the pan.

In the meantime, make the raspberry buttercream by creaming the butter in a medium mixing bowl until creamy and smooth. Mix in the powdered sugar and jam again. To achieve a good piping consistency, add as much heavy cream as needed.

Transfer the raspberry buttercream to a bag fitted with a small round tip or a ziploc bag with one corner cut off to fill the macaron shells. Pipe a buttercream border around the edges of half of the macaron shells. 12 teaspoon raspberry jam, then top with another macaron shells.