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, whisking continuously 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 (macaronage stage).
05 - Transfer batter to pastry bag. Pipe 32 rounds about 1.5 inches each onto prepared sheets. Tap trays firmly to release air bubbles. Let shells rest at room temperature 30-60 minutes until surfaces are dry to touch.
06 - Preheat oven to 300°F. Bake 13-15 minutes, rotating pans halfway through. Shells are done when they easily lift off the mat. Cool completely before filling.
07 - Heat heavy cream until just simmering. Pour over milk chocolate and let stand 2 minutes. Stir until smooth. Add golden syrup and butter, mixing until glossy and emulsified.
08 - Reserve one-quarter of filling and tint with yellow gel coloring for yolk center. Chill both portions until thickened to pipeable consistency.
09 - Pipe a ring of chocolate filling onto one shell. Place a dollop of yellow filling in center. Top with another shell and press gently. Repeat with remaining shells.
10 - Store assembled macarons in airtight container overnight to allow flavors to mature. Refrigerate up to 5 days.