Another birthday, another reason to design a new dessert recipe! Alex organised his party this year around a distinctly 1940s theme, so I thought I’d adapt something that was launched around the same time – the Wagon Wheel biscuit… one of his favourite snacks! The original marshmallow and jam sandwiched between two thin shortbread biscuits becomes a layered delight beginning with a brown butter biscuit base spread with a thin veneer of raspberry jam, smothered with a layer of fluffy marshmallow, and topped off with swirl of dark chocolate.
Although I found a recipe for this slice on-line, it called for store-bought marshmallows, which troubled me somewhat. I wanted to make my own (how hard could it be?), and therefore dug out an old cookbook I’ve had for roughly 20 years now. Published as a fundraiser for a campsite where I used to work, all the recipes are tried and true. One of my favourite fish dishes comes from it, as does my Dad’s signature boiled fruit cake. They included a marshmallow biscuit slice, and I’ve adapted both the base and the marshmallow for this luscious Wagon Wheel Slice.
Because I wanted the option of browning the butter for the base, I’ve gone with melting it instead of creaming the butter with the sugar this time. It yields a nutty, buttery, shortbread-like biscuit, which is exactly what I was hoping for. The raspberry jam was store-bought, of course, but the marshmallow – so easy to make your own – is a whipped confection made with gelatine and lots and lots of sugar. As for that final layer, I chose to use regular dark chocolate; but go with whatever suits your fancy – 70% dark or milk chocolate – it’s up to you!
Wagon Wheel Slice
Layers upon layers of sweet goodness; first the shortbread, then the jam, marshmallow and chocolate. Party food doesn’t get much better than this!
Makes 24 pieces
For the base:
60g (¼ cup + 1 tablespoon) butter or coconut oil, melted
1/3 cup caster (super-fine) sugar
1 egg, beaten*
1 cup + 2 tablespoons plain flour**
¼ teaspoon baking powder
1/3 cup raspberry jam
For the marshmallow:
2 level tablespoons gelatine powder
1 cup water
1 cup caster (super-fine) sugar
1 cup pure icing sugar, sifted
1 teaspoon vanilla extract
185g dark chocolate, broken into pieces (I used dark choc chips)
Preheat oven to 180°C/350F. Grease a 3cm-deep, 16cm x 26cm slice pan or a 23cm (9-inch) square cake tin. Line base and sides with baking paper, extending paper 2cm from edge on long sides.
Melt butter (NB. This is your chance to brown the butter, but this is totally optional). In a heavy-based saucepan, melt butter slowly, then when completely liquid, raise heat and allow to froth, stirring constantly. As froth subsides, butter will begin to stick to pan, creating a brownish substance on the surface of the pan. This is good. The butter should now have a nutty aroma. Once the butter has browned, take off heat immediately, before it burns. Set aside to cool slightly.
Add sugar and egg and mix well. Add sifted flour, baking powder and salt and stir until dough comes together. Press mixture into prepared pan. Bake for 15 minutes or until golden. Spread warm base with jam.
Meanwhile, add 1 cup of cold water to a medium saucepan and sprinkle surface of water with gelatine powder. Allow to sit untouched for at least 10 minutes to allow gelatine to soak (dissolve). Once gelatine is properly soaked, whisk in with a fork. Add 1 cup caster sugar to gelatine mixture and dissolve gently over low heat, then raise heat and boil without stirring for 5 minutes. Remove from heat, allow to cool to room temperature and then add 1 cup of sifted icing sugar.
In a large, deep bowl, beat with an electric mixer until thick and white (should take about 3 to 5 minutes). Add vanilla extract, and beat until well combined. Spoon ½ to ¾ marshmallow mixture over jam layer and place in refrigerator to set. Lightly grease a plastic container with oil and spoon any extra marshmallow into it. Store in refrigerator until you need a snack!
Place the chocolate and butter in a small, clean, dry heatproof bowl. Place the bowl over a small saucepan of barely simmering water over low heat (make sure the bowl doesn’t touch the water). Use a dry metal spoon to stir gently for 2 minutes or until chocolate melts and is smooth. Pour evenly over marshmallow layer and smooth the surface with a knife.
Refrigerate for 2 hours or until set. Stand at room temperature for 5 minutes before cutting into pieces and serving.
*To make this slice egg-free, increase the butter in the base to 75g.
**To make this slice gluten-free, use 1 cup plain (all-purpose) gluten-free flour plus 1/2 cup almond meal (almond flour).