01 - Line a rimmed baking sheet with parchment paper and set aside.
02 - Place the white chocolate in a heatproof bowl set over a saucepan of gently simmering water. Stir continuously until completely smooth and melted. Alternatively, microwave in 30-second intervals, stirring between each burst, until fully melted.
03 - Pour the melted white chocolate onto the prepared baking sheet. Using an offset spatula, spread it into an even rectangle approximately ¼ inch thick.
04 - Melt the semi-sweet or milk chocolate using the same double boiler or microwave method. Drizzle it over the white chocolate layer in thin, random lines. Take a toothpick or wooden skewer and drag it through both layers to create a marbled pattern.
05 - Working quickly before the chocolate sets, scatter the candy robin eggs, pastel sprinkles, and mini chocolate chips evenly across the surface. Gently press the larger candies into the chocolate so they adhere firmly.
06 - Let the bark set at room temperature for 30 to 40 minutes until completely firm. To speed up the process, refrigerate for 15 to 20 minutes.
07 - Once fully hardened, use your hands to break the bark into irregular, generous pieces. Arrange on a serving platter or store for later.