• In the mixing bowl add the lukewarm milk and sprinkle the yeast on top, let sit 5-10 minutes then stir to combine. Add the flour, egg and yolk, mix on #1 speed for 5 minutes, add the zest, salt, sugar and vanilla continue to knead on #1.5 speed for approximately 5-6 minutes, when the dough is elastic and smooth add the butter a little at a time absorbing before adding more, knead until the dough is completely elastic, smooth and semi glossy, approximately 18-20 minutes on speed #2.
• Move the dough to a lightly floured flat surface and form into a ball, place in a lightly buttered bowl, cover with plastic and let rise for 2 hours until doubled. Then place in the fridge for 8-15 hours.
• Remove the ½ cup / 112 g butter from the fridge let sit 30 minutes then roll it between 2 pieces of parchment paper to form a ½ inch / 1 cm rectangle, then place in the fridge.
• Remove the dough from the fridge (it should be tripled), let sit at room temperature for 30-60 minutes. Then place the dough on a floured flat surface and roll into a rectangle ½ inch / 1 cm rectangle approximately 2 x size of the butter rectangle.
• Remove the butter sheet from the fridge and place in the centre of the dough, fold the edges over, so that the edges meet but do not overlap, turn the dough with the open side facing you, gently pat the entire surface with a rolling pin to 9¾x5 inches / 25x13 cm rectangle.
• Roll the dough out to a ½ cm / 1 cm rectangle 13x6¾ inches / 33x17cm. Fold one flap to the centre and the other flap on top, like an envelope. Press down lightly with a rolling pin, wrap in parchment paper and chill one hour. Repeat this procedure two more times.
• After the last fold roll the dough to ½ inch / 1 cm rectangle 15¼ x 9 inches 39x23 cm and cut out triangles, gently stretch each and roll up from the widest part to form a crescent. Place them about 2-3 inches apart on a parchment paper lined baking sheet or two. Cover with a clean tea towel and let rise in a warm draft free area until tripled in size, approximately 4-6 hours.
• Pre-heat oven to 350F/180C.
• Brush the risen cornetti with the egg wash and bake 15-20 minutes or until golden brown. Let cool on a wire rack, dust with powdered sugar before serving. Enjoy!

EGG WASH

• In a small bowl beat together the egg and water.