Dissolve yeast in milk, add egg. Mix in flour, sugar, cardamom, and salt. Knead to form a firm dough.
Work in butter, knead until smooth. Cover and rise 1–2 hours, until doubled.
Line a 40 × 30 cm tray with parchment. Spread dough evenly, press dimples, cover and rise 30 min.
Melt butter and sugar in a pan, stir in cream until combined (don't boil). Cool slightly.
Preheat oven to 200 °C. Make new dimples, spread topping evenly.
Bake 20–25 min. Cool 10 min on a rack before serving.
