Step 1
Sift confectioners' sugar into a medium bowl. Sift in coconut flour.
Step 2
Beat egg whites in a separate bowl using an electric mixer until white and foamy. Add white sugar slowly. Beat until mixture is glossy and forms stiff peaks.
Step 3
Sift the coconut flour mixture into the egg whites a few tablespoons at a time folding after each addition. Batter should be thick and gooey and able to fall off a spoon slowly like lava.
Step 4
Fit a piping bag with a coupler and a tip. Drop piping bag tip-down into a tall glass and fold edges down around the glass. Spoon batter into the bag. Gather edges and twist together.
Step 5
Holding the tip at a 90 degree angle pipe batter onto a greased baking sheet to form individual macaron shells. Tap baking sheet onto a countertop to remove air bubbles. Let sit until dry 15 to 60 minutes.
Step 6
Preheat the oven to 300 degrees F (150 degrees C).
Step 7
Bake in the preheated oven until tops are firm 15 to 20 minutes.
Step 8
Puree raspberries in a food processor adding water if using frozen raspberries. Strain out the seeds using a fine-mesh strainer.
Step 9
Beat butter and 1/2 the confectioners' sugar in a bowl using an electric mixer until combined. Add the remaining 1/2 and beat until creamy. Add raspberry puree and heavy cream; mix well to make the frosting.
Step 9
Spoon a small amount of frosting over the flat side of a macaron shell; cap with another shell. Repeat with the remaining filling and shells.