Step 1

Grease and line the base and side of a 19 x 29cm slice pan with baking paper, allowing the sides to overhang.

Step 2

Combine the butter, golden syrup and three-quarters of the Mars bars in a medium saucepan over low heat. Cook, stirring with a wooden spoon, for 5 minutes or until Mars bars and butter melt and mixture is smooth. Remove from heat.

Step 3

Place the rice bubbles and remaining Mars bar in a large bowl. Add the Mars bar mixture and stir until well combined. Spoon into the prepared pan and use the back of a spoon to smooth the surface. Set aside for 1 hour to cool completely.

Step 4

Place the chocolate and copha in a heatproof bowl over a saucepan half-filled with simmering water, stir until chocolate melts. Pour chocolate over the top of the slice to evenly coat. Set aside for 30 minutes to set. Cut into squares to serve.