Preheat your oven to 350°F. While it heats, gather all ingredients and bring the 4 large eggs and 2 egg yolks to room temperature (about 70°F)—this ensures even mixing and a more tender crumb. Measure out the flour, sift the powdered sugar to remove lumps, and have all other ingredients ready. Grease and flour two round cake pans (8 or 9-inch), or line them with parchment paper for easier removal.

In a large mixing bowl, cream together the 7 oz butter, sugar, salt, and baking powder for about 5 minutes until the mixture is light, fluffy, and pale—this incorporates air for a tender cake. Beat in the eggs one at a time, making sure each is fully incorporated before adding the next. I like to scrape down the bowl between additions to ensure even mixing. This method creates a stable emulsion that will hold more air and give you a beautiful, light crumb.

Alternate adding the flour and milk to the creamed mixture in stages—start with about one-third of the flour, then half the milk, then another third of the flour, then the remaining milk, and finish with the final third of flour. Mix gently between additions to avoid overdeveloping the gluten. Stir in the 2 egg yolks and both vanilla extracts (3 tsp vanilla extract and 1/2 tsp coconut extract) until just combined. Divide the batter evenly between the prepared pans and bake for 25-30 minutes until a toothpick inserted in the center comes out clean. Cool the cakes in their pans for 10 minutes, then turn them out onto wire racks to cool completely—this prevents them from becoming dense and ensures clean layers for stacking.

While the cakes cool, whip together the mascarpone and 6 oz softened butter in a clean bowl for about 5 minutes until light and fluffy. Gradually add the sifted powdered sugar and 4 tsp vanilla extract, mixing until the frosting reaches a spreadable consistency. I like to do this by hand with a whisk or use an electric mixer on medium speed—this prevents overworking the mascarpone, which can become grainy if whipped too vigorously. The frosting should be smooth, creamy, and hold its shape.

Once the cakes from Step 3 are completely cool, place one layer on a serving plate or cake stand and spread a generous layer of mascarpone frosting from Step 4 on top. Stack the second cake layer and apply frosting to the top and sides, creating an even crumb coat. Chill the frosted cake for 20 minutes—this firms up the frosting and makes it easier to apply any decorative details.

While the cake chills, place the 4 oz sweetened flaked coconut in a small bowl and add a few drops of green food coloring, stirring well until the coconut is evenly dyed a soft green. Remove the cake from the chill and, if desired, pipe frosting flowers or rosettes on top using the remaining frosting from Step 4 and a piping bag with a decorative tip. Generously coat the top with the green coconut and arrange the 12 oz robin egg candies decoratively on top, pressing them gently into the frosting to secure them.

Chill the finished cake for at least 30 minutes before serving to allow the frosting to set and the flavors to meld. The cake can be made a day ahead and stored in an airtight container in the refrigerator—just add the fresh frosting decorations and candies a few hours before serving for the best presentation.