The GBBO week 2 challenges included Viennese Whirls, which usually are plain biscuits sandwiched with vanilla buttercream & jam.
I decided to make a gluten-free chocolate version, with melted chocolate instead of jam. I’ve added a hint of coffee which enhances chocolate flavours.
Makes: 12 sandwiched biscuits (24 individual)
For the biscuits:
- 240g unsalted butter, cubed and softened
- 80g icing sugar
- 40g cocoa
- 1 tsp vanilla extract
- 40g cornflour
- 200g gluten-free flour
- 1 tsp instant coffee powder
- 1 tsp gluten-free baking powder (only if your GF flour is plain, not self-raising)
- 1/2 tsp ground cinnamon (optional)
For the chocolate and buttercream:
- 100g dark baking chocolate (min 70% cocoa solids), broken into squares
- 2 tablespoons soft dark brown sugar (approx 30g)
- 1 tsp instant coffee powder, or coffee extract
- 150g unsalted butter, cubed and softened
- 260g icing sugar (weighed un-sifted)
- 1 tsp vanilla extract
- Icing sugar, to decorate (optional)
- 2 baking trays
- Baking/parchment paper to line both trays
- 2 large and 1 small mixing bowls
- Electric mixer (hand-held or stand)
- 2 piping bags with 2 star nozzles (1 large and 1 small) – See Footnote
- Cooling rack
- Small saucepan, with a small bowl that fits over
Making the biscuits:
- Preheat oven to 180 C (160 C fan-assisted). Line both trays with baking paper.
- Whisk the butter, icing sugar, cocoa, and vanilla in a large bowl on medium-high speed until creamy.
- Combine the cornflour, flour, coffee, and baking powder and spice (if using) in a medium bowl with a fork.
- Sift the dry ingredients into the creamed butter and fold manually until well combined (this can be easier to do by adding in a third at a time). The dough should be rather ‘tacky’, not creamy.
- Spoon the dough into a piping bag fitted with a large star nozzle. Pipe 2″ swirls (see Footnote) 3x4 on your prepared baking sheets. If you’re finding it really difficult to pipe, pop the bag into the microwave for 7-10 seconds on high, then try again. (Be aware if you do this, the biscuits will spread out during baking, so leave plenty of room between.)
- Bake for 12-15 minutes, turning trays halfway through for even baking, until they feel firm to a light touch. Remove the trays from the oven; let the biscuits cool for 5 minutes to further firm up before transferring them carefully to a cooling rack (they are very crumbly when mis-handled).
Making the chocolate & buttercream:
- While the biscuits are cooling, place the chocolate, brown sugar, and coffee in a small bowl that fits over a saucepan filled with simmering water (don’t let the bottom of the bowl touch the water). Stir until the chocolate is fully melted and the sugar and coffee are incorporated. Remove from the heat and leave the bowl to cool.
- Whisk the butter and icing sugar at medium-high speed in a large bowl until it’s fluffy. Add the vanilla and keep whisking until it’s thoroughly combined.
- Transfer the buttercream to a piping bag with a small star nozzle (see Footnote). Set aside until ready to use.
- Match up biscuits by size to make pairs. Take 1 of each pair, and spoon the chocolate in a generous dollop in the centre. Leave upside down on the cooling rack.
- Take the 2nd of each pair, and pipe the cream generously in the centre (see Footnote).
- Sandwich the pairs together. If you like, you can dust them with icing sugar before serving.
Piping the Biscuit Dough and Buttercream
This video demonstrates the proper technique for swirling frosting on a cupcake, which is the same technique to use for the biscuits and buttercream here (i.e., start in the middle and swirl outward in a circle).
If you like, you could dispense with fancy nozzles, and just pipe both the biscuits and the buttercream through a snipped-off end of a piping bag. Use a 1/2″ width for the bisuits, and a smaller width for the cream. The dough is designed to be piped, though, not shaped into discs with your hands, so I wouldn’t try that.