01 - Line two baking sheets with parchment paper or silicone mats. Fit a pastry bag with a 0.5-inch round tip.
02 - Sift almond flour and powdered sugar together into a bowl. Set aside.
03 - In a clean, dry bowl, whisk egg whites and cream of tartar until soft peaks form. Gradually add granulated sugar while whisking until stiff, glossy peaks form.
04 - Gently fold almond flour mixture into meringue in three additions. Optionally tint one-third of batter yellow for yolk effect. Mix until batter flows in thick ribbons and dissolves back into itself within 20 seconds.
05 - Transfer batter to pastry bag. Pipe 32 rounds (1.5 inches diameter) onto prepared sheets. Firmly tap trays to release air bubbles. Let shells rest at room temperature for 30 to 60 minutes until surfaces form dry skin.
06 - Preheat oven to 300°F. Bake for 13 to 15 minutes, rotating trays halfway. Shells are done when they easily lift from mat without sticking. Cool completely before filling.
07 - Heat heavy cream until just simmering. Pour over chopped milk chocolate and let sit 2 minutes. Stir until smooth. Add golden syrup and butter, mixing until glossy and emulsified.
08 - Separate one-quarter of ganache and tint with yellow gel coloring for yolk effect. Refrigerate both portions until thickened to piping consistency, approximately 30 minutes.
09 - Pipe a ring of chocolate ganache on one shell. Place a dollop of yellow filling in center. Gently sandwich with second shell. Repeat with remaining components.
10 - Place assembled macarons in airtight container. Refrigerate for 24 hours to allow flavors to mature and texture to develop properly. Store up to 5 days refrigerated.