Prep & Sift Dry Ingredients:Sift together 1 cup almond flour, 1 cup powdered sweetener, and 1 Tbsp coconut flour twice to remove lumps. Set aside. Line two baking sheets with silicone mats or parchment paper.
Whip Egg Whites:Let 3 large egg whites sit at room temperature for 30 minutes. In a clean, grease-free bowl, add ⅛ tsp cream of tartar to egg whites. Using a mixer, beat on medium speed until foamy.
Add Sweetener & Beat:Gradually add ¼ cup powdered sweetener from dry mix while whipping. Continue beating on high speed until stiff, glossy peaks form.
Fold Dry Mix Into Meringue:Gently fold sifted dry ingredients into the meringue in three additions using a spatula. Fold until batter flows in a thick ribbon and settles after about 10 seconds.
Pipe Macaron Shells:Transfer batter into a piping bag fitted with a ½-inch round tip. Pipe 1½-inch circles onto lined baking sheets, spaced about 1 inch apart.
Tap & Rest:Firmly tap baking sheets on the counter 3 times to release air bubbles. Let shells rest at room temperature for 30–60 minutes until a dry “skin” forms (no batter sticks to touch).
Bake:Preheat oven to 290°F (145°C). Bake shells for 14–16 minutes, rotating halfway through. Shells should be firm and develop small “feet.”
Cool:Remove from oven and let macarons cool completely on mats before peeling off.
Prepare Filling:For ganache: Heat ¼ cup heavy or coconut cream; pour over 4 oz sugar-free chocolate. Stir until smooth and cool until pipeable.For buttercream: Whip ½ cup softened unsalted butter, gradually add ½ cup powdered sweetener, 1 tsp vanilla, and a pinch of salt until light and fluffy. Assemble Macarons:Match shells by size. Pipe filling onto one shell, then top with a matching shell. Press gently to spread filling.
Chill:Refrigerate assembled macarons for 24 hours for best texture and flavor. Bring to room temperature 30 minutes before serving.