Line a 9x13 inch pan with parchment and lightly grease it.

Melt the butter in a large pot over low heat, then add the marshmallows and stir constantly until fully melted and smooth.

Remove from heat and fold in the rice cereal until every piece is coated.

Press the mixture firmly and evenly into the prepared pan using a greased spatula or your greased hands.

Let the pan cool for 20 minutes, until firm enough to hold a shape when cut.

Use a round cutter about 2 inches across to cut the treats into coin shapes, re-pressing scraps together for a few more rounds.

Melt the white chocolate in short bursts in the microwave, stirring between each, then stir in the yellow food coloring until evenly pale gold.

Dip half of each coin into the melted chocolate and set it on parchment, then scatter gold sanding sugar over the wet chocolate before it sets.

Let the coins sit at room temperature for 15 minutes, until the chocolate hardens fully, before stacking or serving.