01 - Line two baking sheets with parchment paper or silicone mats. Fit a pastry bag with a 1/2-inch round tip and set aside.
02 - Sift almond flour and powdered sugar together into a large bowl. Repeat sifting twice to ensure a fine texture. Set the mixture aside.
03 - In a clean, dry bowl, beat egg whites and cream of tartar with an electric mixer until soft peaks form. Gradually add granulated sugar while beating, continuing until stiff, glossy peaks form.
04 - Gently fold the almond flour mixture into the meringue in three additions. For a yolk effect, tint one-third of the batter yellow. Mix until the batter flows in thick ribbons from the spatula and disappears back into itself within 20 seconds.
05 - Transfer the batter to the prepared pastry bag. Pipe 32 rounds approximately 1.5 inches in diameter onto the baking sheets, spacing them 2 inches apart. Firmly tap the trays against the counter several times to release trapped air bubbles.
06 - Let piped shells rest at room temperature for 30 to 60 minutes until the surface is completely dry and no longer sticky to the touch. Preheat oven to 300°F. Bake for 13 to 15 minutes, rotating trays halfway through. Shells are done when they easily lift off the baking surface. Cool completely.
07 - Heat heavy cream in a small saucepan until just simmering. Pour over chopped milk chocolate and let stand for 2 minutes. Stir until smooth and glossy. Add golden syrup and softened butter, mixing until fully incorporated. Chill until thickened but still spreadable.
08 - Reserve one-quarter of the chocolate filling and tint with yellow gel food coloring for the egg yolk effect. Keep both fillings at room temperature for assembly.
09 - Pipe a ring of chocolate ganache onto the flat side of one shell. Place a small dollop of yellow filling in the center. Gently press another shell on top to create a sandwich. Repeat with remaining shells and filling.
10 - Transfer assembled macarons to an airtight container. Refrigerate for 24 hours to allow flavors to mature and textures to develop fully. Best consumed within 5 days.