Grease and flour or grease and line a 24cm cake tin and set aside.
Place all ingredients into a bowl and mix on high for 4 minutes.
Pour into lined muffin containers and bake for about 12-15 minutes or until the cakes springs back when lightly touched in the centre.
When cool, create the surprise in the middle of the cupcakes.
Using a corer, create a well in the middle of each cupcake. Save the part of the cupcake you remove.
Fill the well of each cupcake with mini M&Ms. Top the well with the removed piece of cupcake.
To Make the Icing
To make the icing, sift the icing sugar into a medium bowl.
Add the butter and water, and stir with a wooden spoon until smooth.
Spread a smooth layer of icing over the cupcake and invert the cupcake, pressing into the cookie crumbs. Set the cupcake aside.
Buried Treasure Topper
Melt the milk chocolate melts in a microwave safe bowl by microwaving for 30 seconds and then stirring vigorously. Repeat in the microwave in 10 second increments as needed until completely melted. Do not overheat as the chocolate will seize. If the chocolate hardens, stir in 1 teaspoon of coconut oil or vegetable shortening.
Open the nugget candies. Spread a small amount of the melted chocolate on the flat side of a candy. Dip the wet chocolate into the gold sprinkles. Allow to dry.
Spread the melted chocolate on the flat side of another nugget. Press the wet chocolate against the sprinkles. Allow to set until the chocolate has solidified.
Dab a tiny amount of icing on the bottom of the treasure chest and press into the top of the cupcake.
Nutritional information is an estimate and provided as a courtesy. The values may vary according to the ingredients and tools that are used. Please use your preferred nutritional calculator for more detailed information.