For the sugar syrup:
50ml sugar
50ml water
For the frangipane:
100g butter, softened
100g caster sugar
1 egg
100g ground almonds
1 Tbsp flour
To assemble:
3 hot cross buns, cut in half
1 bunch rhubarb
Icing sugar, for dusting
For the sugar syrup:
In a saucepan, bring the sugar and water to a simmer until the sugar dissolves. Set aside to cool. (This can be made ahead).
For the frangipane:
In a food processor, blend the butter and sugar until creamy. Add the egg and beat well, then add the almonds and flour. Set aside (this can be made ahead and refrigerated, but bring it to room temperature before using).
This makes more than required for three buns, but you can easily freeze it to use at a later date!
To assemble:
Preheat the oven to 180 degrees (160 degrees fan).
Line a baking tray with baking paper. Lay the hot cross buns on the tray and brush with the sugar syrup. Spread the frangipane onto the cut side of each bun with a spoon or small spatula. Cut the rhubarb into lengths long enough to make cross for each bun.
Bake for 20-25 minutes, until the frangipane is golden. Cool for 5 minutes and dust with icing sugar to serve.