Preheat the oven to 180°C, then generously brush 16 mini muffin pans (40mls/2 tablespoons each) with melted butter or margarine to grease lightly.
Combine the flour, baking powder, and nutmeg in a medium mixing bowl by sifting them together. Add the brown sugar and mix well. In a separate jug, combine the buttermilk, melted butter, and egg, whisking until fully combined.
Gently combine the buttermilk mixture with the dry ingredients using a metal spoon. Divide half of the mixture evenly into the muffin pans. Place a caramel-filled egg upright in the center of each muffin. Top with the remaining mixture, ensuring eggs are fully covered.
Bake in a preheated oven until golden, usually for 18-20 minutes. Let the cakes rest in the pans for 5 minutes before transferring to a wire rack. Serve while still warm.