Swedish Semlor (Lent Cream Buns with Cardamom & Almond Paste)

Name: Swedish Semlor (Lent Cream Buns with Cardamom & Almond Paste)
Cuisine: European
Ingredients: 75g (⅓ cup) butter; 300ml (1¼ cups) milk; 50g (1¾ oz) fresh yeast (see note 1); 1 egg; 55g (¼ cup) sugar; 1 teaspoon cardamom powder; 400-500g (4-5 cups) spelt flour (see note 2); 100g (3½ oz) almonds (see note 3); 100g (½ cup) sugar; 1 tablespoon milk; 500ml (2 cups) whipping cream (36% fat); Icing / powdered sugar (for dusting)