Line a baking dish or try with tinfoil or grease-proof paper with an overhang: this will make it easier to lift the out when ready.
Crush the Oreos and pour into a bowl (I put them in a bag and bash them with a rolling pin).
Cut some of the Maltesers in half, and leave the rest whole.
Cut the fudge into small pieces, then add them to the crushed cookies.
Stir so that everything is evenly distributed.
In a large pan, gently heat the butter, syrup and chocolate, just until melted.
Add the dried ingredients, and stir until just combined.
Pour into the prepared tin, spread until fairly even, and push whole Maltesers gently into the top.
Leave in the fridge until completely hardened. Remove from the tin and cut up into small pieces (either squares or slices). Enjoy!