How to make
Preheat the oven to 360°F (180 °C). You're going to need a flat tray with baking paper.
Mix together the yeast, sugar and a little milk in a small bowl. Leave it to activate for 10 min. Add the yolk and melted butter (now at room temperature). Stir.
Pour the flour, salt, liquid mixture, the rest of the milk in a mixer bowl and knead a dough until it begins to come off the walls of the mixer bowl. Place this dough in a lightly buttered bowl, cover with foil and leave it to rise for about 1 hour.
In a separate bowl, mix the softened butter, brown sugar, cinnamon, ground almonds.
On a floured counter, form the dough into a rectangle using a rolling pin. Use a spoon to place the filling, leaving a 1/2 (1 cm) space without filling around the edge of the dough.
Form it into a tight roll and cut it down the middle with a sharp knife but leave about 1 1/2″ (3 cm) uncut at the end, to keep it connected.
Twist the 2 threads about each other, while making sure the cuts are facing up. Shape it into a wreath and transfer to the flat tray. Smear it with yolk and sprinkle with light brown sugar.
Bake at 360°F (180 °C) about 30 min.