This s’more brownie recipe has everything you'd hope for and...s'more! A crisp biscuit base, a rich chocolate brownie middle and a gooey marshmallow top.
Grease and line a 20cm x 28cm (8 inch x 11 inch) non-stick shallow rectangular cake tin.
Crush the biscuits to a crumb in a food processor or in a bag with a rolling pin. Tip into a bowl.
Add the melted butter and mix together.
Press the biscuit mixture into the bottom of the tin.
Bake in the oven for 10 minutes to help firm it, then remove from the oven and set aside to cool and firm up.
For the brownie layer
Put the butter and chopped dark chocolate in a large, heatproof bowl. Gently melt until smooth. You can use the microwave to do this, using 30 second bursts and stirring after each burst. Alternatively, you can put an inch of water in a pan, place the bowl on top (so that the water isn't touching the bowl) and bring to the boil so that the steam gently melts the chocolate, stirring as you go.
Whisk the sugar in. The mixture will thicken - graininess at this stage is fine.
If the mixture is hot, wait until it's just slightly warm before adding the beaten egg and vanilla. Whisk together until smooth.
Sift the flour into the bowl. Gently fold through until evenly combined.
Bake for 35-40 minutes until set all the way across. A skewer pushed into the centre should reveal sticky crumbs.
To make the topping
Switch the oven to grill (broiler) setting.
Arrange the marshmallows in a single layer to cover the whole top of the brownie.
Place the brownies under the grill (broiler) for about 5 minutes until they begin to turn golden on top. Keep a close eye as they can go from pleasingly browned to burnt and blackened in moments.
Remove from the oven and place on a wire rack to cool completely.
Place in the fridge to chill overnight, then your brownies can be cut into squares.