First dissolve the yeast in barely warm water.
Place the flour in a bowl and pour the sugar, egg yolk and water with yeast into the center.
Start kneading, then add the butter a little at a time, waiting for it to be absorbed well before adding more.
Once you have obtained a soft and homogeneous dough, let it rise in a covered bowl for at least 2 hours or until it doubles in size.
Divide the dough into 8 loaves of about 70 g each, shape into balls and leave to rise for at least 30 minutes on the baking tray lined with baking paper.
After resting, brush with egg white and cook for about 15 minutes at 190°C, in a pre-heated static oven, then remove from the oven and leave to cool.
In the meantime, prepare the almond paste: put the almonds in a mixer with sugar, icing sugar, water and vanilla.
Once you have obtained a homogeneous but sticky mixture, cover it with cling film and leave to rest in the fridge for at least 15 minutes.
When the brioches are cold, proceed with the filling: whip the cream, well cold from the fridge.
Then add the almond paste to the whipped cream, mixing delicately, then transfer the cream into a piping bag with a star-shaped nozzle that is not too narrow.
Take the brioche, cut the top and scoop out some of the crumb from the center to create a small cavity.
Fill the brioches and reposition the top, without crushing too much.
The Swedish semla are ready, all you have to do is decorate them with icing sugar and serve them.
