These are heart-shaped custard creams made festive: more generous and well-defined spice amounts, a little rum extract in the filling, and the suggestion you make them star-shaped. Twee? Yes. And they’re delicious.
These little stars are best the day after they’re made: the cookie melds with the nutmeg and rum flavoured buttercream while still remaining light and crisp. Letting them set for a good few hours also bolsters structure–all of those frangible points!–so you can gift them as usual, if you wish. However, I also understand if you want to keep them safely for yourself.
Makes at least 25 sandwich cookies (50 individual cookies). Filled cookies keep for at least 7 days in an airtight tin.
Dough can be chilled overnight or frozen for 3 months. Once thawed (which takes a couple of hours), use within 24 hours.
Finding/substituting rum flavouring: Most larger branches of UK supermarkets sell own-brand rum flavouring in their home baking section with all the other little bottles of flavourings and colourings. It should cost about £1. You can of course order online; frequently you can get higher grade extracts, but watch the intensity–add to taste.
You could use actual rum, but since you’ll have to use double the amount of liquid to get the same intensity of flavour, increase the icing sugar slightly.
alternative doughs & fillings: I use simple buttercream for ease of gifting, but if you can ensure the biscuits are refrigerated til serving time, try a French or German buttercream or this amazing-sounding eggnog filling.
On the brighter end of the spectrum, a citrus curd filling would be nice. And you can of course use any sugar cookie dough you like.
90g/2/3 cup plain flour
1 1/2 tbsp Bird’s custard powder
1 1/2 tbsp granulated sugar
1/4 tsp baking powder
1/4 tsp freshly grated nutmeg, packed (slightly less if using ready ground)
1/8 tsp ground cinnamon or mixed spice
Pinch of salt
50g/3 1/2 tbsp unsalted butter, cold, cut into dice
1 egg yolk, any size
2 tbsp milk, more if needed
eggnog cream filling:
1/2 tbsp Bird’s custard powder
1/2 tsp freshly grated nutmeg, plus more for sprinkling
1/8 tsp ground cinnamon or mixed spice
Tiny pinch of salt
50g/1/3 cup icing sugar, sifted
25g/2 tbsp soft unsalted butter
scant 1/4 tsp vanilla extract
scant 1/4 tsp rum flavouring or extract
A few drops of almond extract (optional)
1/2 tsp hot water
freshly grated nutmeg
edible glitter or similar (optional)
5cm/2 inch star cutter (measured left to right from point to point)
Piping bag/bottle, or clean sandwich bag/baking paper to make your own. Piping tip or opening should be 3 – 4 mm.
For the biscuits, mix plain flour, custard powder, sugar, baking powder, grated nutmeg, cinnamon, and salt in a medium mixing bowl. Add diced butter and cut it into the flour with a pastry blender until mixture resembles fine breadcrumbs.
In a small bowl, combine egg yolk and milk. Add half of this to the flour mixture, blending well with a round-bladed knife until larger crumbs form; mixture will look dry but should be soft enough to press together into a cohesive dough. Add more liquid only as needed and use your hands to bring everything together. Pat dough into a disc, wrap and refrigerate for 20 – 30 minutes, or until completely cool and firm.
When you’re ready to bake, preheat oven to 180 degrees Celsius/160 fan (350 degrees F). Line 2 large baking trays with paper. If dough is rock solid, rest at room temperature for 10 – 20 minutes until malleable.
On lightly flour-dusted surface, roll dough until it’s about as thin as a £1 coin (3 mm/1/8 inch). Cut out shapes with a 5 cm/2 inch star cutter and gently place onto baking tray a couple centimetres apart (these biscuits won’t spread much). Loosely gather scraps into clingfilm and allow to in the fridge while you finish the batch.
Bake biscuits for 9 – 10 minutes, rotating trays halfway. They’re done when dry on top and just turning gold at the tips. Completely cool biscuits on racks before icing. Repeat with remaining scraps, ensuring there’s enough to make desired amount of sandwich biscuits.
In the meantime, make the buttercream filling. Mix custard powder, nutmeg, cinnamon, salt, and icing sugar together in a small mixing bowl, making sure there are no lumps. Add soft butter, the vanilla, rum, and almond extracts, plus the hot water, beating well with a fork until creamy and light. Taste, adding more grated nutmeg, salt, and extracts/flavouring if needed.
To assemble, transfer buttercream to a piping bag or bottle with an opening no bigger than 3 ~ 4 mm (approx 1/8 inch). Carefully pipe a good layer of filling onto the back of a biscuit, working outwards from the middle to each star-point. Rather than zig-zagging for coverage, hold the tip in the middle and pipe a big blob on the spot, then gently draw the tip outwards to gently taper. There’s more than enough buttercream to fill these, so pipe generously and with no fear. (You can use a teaspoon but it will be more stressful. A DIY piping bag made from a plastic bag or baking paper is perfect.)
Grate fresh nutmeg over the filled biscuits. Brush or sprinkle over glitter if using. Leave filling to set before storing them, ideally for a couple of hours or overnight in a single layer.