Line an 8x8 inch baking pan with foil, making sure there's enough overhang on the sides for easy lifting later. Set aside 9 whole mini eggs, and chop the rest into different sizes for varied texture.
For the chocolate layer, combine the semi-sweet chocolate chips, 7 ounces of condensed milk, and 2 tablespoons of marshmallow creme in a medium saucepan. Heat over medium flame, stirring constantly until smooth and fully melted.
Pour the chocolate mixture into the prepared pan and spread it evenly with a spatula to form the base.
For the white layer, place the white chocolate chips, remaining 7 ounces of condensed milk, and 2 tablespoons of marshmallow creme in another saucepan. Heat and stir until melted and blended.
Take the white mixture off the heat and stir in the vanilla extract. Gently fold in the 1/3 cup of sprinkles, mixing just enough to distribute without bleeding colors.
Pour the white mixture over the chocolate layer and spread it smoothly to cover.
Sprinkle the extra tablespoon of sprinkles on top. Arrange the 9 whole mini eggs in rows, then scatter the chopped eggs around them for decoration.
Cover with foil and chill in the refrigerator for 4 hours until firm, or let it set at room temperature overnight if preferred.
Once set, use the foil overhangs to lift the fudge out. Flip it onto a cutting board, remove the foil from the bottom, and flip back. Let it sit for 20 minutes if too firm, then cut into squares.
