S’more Cookie Bars

Preheat the oven to 180°C (350°F), Gas Mark 4. Lightly grease the baking tin, then line with a piece of parchment paper that overhangs the two long sides of the tin. Secure the paper in place with two metal clips.

For the base, add the digestives or graham crackers to a food processor and pulse a few times to break into crumbs with some little chunks remaining (we don’t want a super fine powder), then tip into a bowl and set aside. Add the flour and sugar to the food processor and pulse to combine. Add the butter and pulse until the mixture just starts to clump together, then add the biscuit crumbs and pulse a couple of times to mix. Scrape the mixture into the prepared tin and use a glass to press it into a flat, even layer. Refrigerate for 20 minutes.

Bake the base for about 30 minutes, or until golden brown. Set aside to cool completely in the tin.

For the filling, place the chocolate into a heatproof bowl. Place the cream, vanilla and salt into a saucepan and bring to a simmer over a medium heat. Pour the hot cream over the chocolate and set aside for a couple of minutes, then stir to form a smooth, glossy ganache. Pour over the cooled base, spreading evenly.

Refrigerate for at least an hour, or until the ganache is firm.

Scatter over the mini marshmallows in an even layer, trying to ensure the ganache is fully covered. Preheat the grill to high. Place the baking tin under the grill and cook until the marshmallows are as dark as you like, but don’t walk away as the marshmallows will toast quickly.

Set the bars aside at room temperature for 30 minutes to allow the marshmallows to cool. Once cooled, lift the bars out of the tin and place onto a chopping board (using the parchment paper to help). These can be a little messy to cut, so if you want neat slices, between each cut, dip the knife in hot water and wipe dry. Store in a sealed container for 4 days.