Place flour in a mixing bowl and make a well in the centre. Combine yeast and milk and stir in. Let rise 15 minutes.
Add melted butter, sugar, egg, salt and zest. Mix well, cover and let rise in a warm place until doubled in size.
Separate dough into 3, roll out into sausages and braid. Twist into a wreath and put on a baking tray lined with baking paper. Preheat oven to 220 degrees C.
Brush the wreath with beaten egg yolk and sprinkle with almonds. Combine sugar and rum and drizzle over. Bake 40-60 minutes, or until well browned.