Grease a slice tin and line with baking paper, leaving extra on each side (to pull the slice from the tin once cooked).
Mix all ingredients together. Press into slice tin and level out with the back of a spoon.
Bake for 20 minutes.
Peppermint Filling
Beat butter until a pale colour.
Add icing sugar gradually, beating after each addition. Beat until fluffy.
Add peppermint essence and green colouring and beat again.
Once base is completely cooled, spread peppermint filling evenly over the base.
Chocolate Topping
Melt chocolate by placing in microwave and heating with 20 second bursts (stirring between each burst).
Pour melted chocolate over cream filling, tilting tin from corner to corner to spread chocolate completely over the peppermint filling.
Place in fridge for 15-30 minutes. Ideally, the chocolate shouldn't be completely set when cutting (it will crack as you're cutting if it's too hard).
Once set, remove slice from tin by lifting edges of baking paper, cut into squares and return to the fridge. (And if you've left the slice in the fridge for longer, just let the slice rest at room temperature for half an hour before cutting into squares.)
Notes
Storing: Store this slice in an airtight container in the fridge for up to 5 days.Freezing: You can also freeze it – wrap well and place in an airtight container before freezing for up to 2 months.Nutrition: The nutrition information is an automatically generated estimate and is not guaranteed to be accurate.