01 -
Sift almond flour and powdered sugar together 2-3 times to ensure it's super fine and smooth. Set aside.
02 -
Whip room temperature egg whites until soft peaks form. Gradually add granulated sugar and beat until stiff peaks form. Add food coloring if using.
03 -
Gently fold dry ingredients into egg whites in two batches until batter flows like lava and forms ribbons that disappear in 10-15 seconds.
04 -
Pipe 1.5-inch circles onto lined baking sheets. Tap sheets firmly to remove air bubbles. Let rest 30-60 minutes until tops are dry to touch.
05 -
Bake at 300°F for 15-18 minutes, rotating halfway, until shells have formed feet and are set. Let cool completely.
06 -
Beat butter until creamy, gradually add powdered sugar and vanilla. Add milk as needed for spreadable consistency.
07 -
Match shells by size, pipe filling on one shell and sandwich with another. Refrigerate 24-48 hours to mature.