Step-by-Step Preparation

1: Prepare the Slice Tin

1. Grease and line a 20 cm x 20 cm square baking tin with baking paper.
2. Leave a 2 cm overhang on the sides to help lift the slice out later.

2: Make the Chocolate Cookie Base

1. Crush the chocolate cookies in a food processor until they form fine crumbs.
   • No food processor? Place the cookies in a zip-lock bag and crush with a rolling pin.
2. Pour in the melted butter and stir until the crumbs are fully coated and look like wet sand.
3. Press the mixture firmly and evenly into the base of the prepared tin using the back of a spoon or glass.
4. Place in the fridge to chill for 15–20 minutes while you prepare the mint layer.

3: Make the Mint Cream Layer

1. In a medium bowl, beat the softened butter with the milk and peppermint extract.
2. Gradually add the powdered sugar, beating until smooth and creamy.
3. Add 2–3 drops of green food colouring (optional) and stir until you reach your desired minty hue.
4. Spread the peppermint cream evenly over the chilled biscuit base.
5. Return the tin to the fridge for at least 30 minutes to allow the layer to firm up before adding the ganache.

4: Make the Chocolate Ganache Topping

1. Place the chopped chocolate in a heatproof bowl.
2. Heat the cream in a small saucepan over medium heat until it just begins to simmer (do not boil).
3. Pour the hot cream over the chocolate and let it sit for 2–3 minutes.
4. Stir gently until the mixture is smooth and glossy.
5. Let the ganache cool for 5 minutes, then pour it over the mint layer, smoothing it with an offset spatula or spoon.
6. Refrigerate for at least 2 hours, or until the slice is fully set.

5: Slice & Serve

1. Once chilled and set, lift the slice out of the tin using the baking paper overhang.
2. Use a warm, sharp knife to slice into squares or bars. Wipe the knife clean between cuts for tidy edges.
3. Serve chilled or at room temperature.