Mix flour, salt, sugar, yeast, butter, milk, and 150ml water in a mixer for 5 minutes.
Cover and leave the dough to prove in a warm place for 1 hour until doubled.
Divide dough into two parts, kneading cardamom into one and nutmeg into the other.
Divide each part into 8 pieces, shaping the cardamom dough into balls and nutmeg into fingers.
Place on trays, cover, and prove for 30 minutes.
Bake in a preheated oven at 200°C for 10 minutes.
Heat milk and sugar for the custard, then stir into whisked egg yolks and cornflour.
Thicken custard over heat, stir in salt and almond extract, then cool completely.
Fold whipped cream into the cooled custard.
Blend cherries, boil with sugar and lemon juice to 105°C, cool, and sieve.
Make royal icing by beating egg white, lemon juice, and icing sugar into a smooth paste.
Whip double cream and icing sugar together to make Chantilly cream and chill.
Halve cardamom buns horizontally, fill with custard, and top with icing, almonds, and cardamom.
Slit nutmeg fingers, pipe icing on sides to set, then fill with jam and cream.