In a large bowl, combine flour, yeast, sugar and salt. Make a well in the centre and pour in warm milk, melted butter and egg yolks. Mix with floured hands until all ingredients are combined and dough starts to come together.
Tip dough out onto a well-floured surface and knead until smooth about 7-8 minutes. Place the dough in a lightly greased bowl, cover with cling wrap and prove for 1 to 1 ½ hours until the dough has doubled in size.
Punch down the dough, place onto a lightly floured surface and knead lightly for about 2 minutes. With a floured rolling pin, roll out the dough to 1cm thickness.
With an 8cm oval cutter, cut out each ghost doughnut (A round cutter can also be used, with the dough stretched out to an oval shape before cutting out the eyes and mouth). Use a 1cm cutter to cut out the eyes and mouth. Set aside on a lined tray to rise slightly for another 15 minutes.
Heat oil in a heavy based pan and fry each doughnut for about 40 seconds on each side until puffed and golden in colour. Place onto a tray lined with paper towel to absorb any excess oil. Repeat the process with the remaining donuts.
Dust with icing sugar and/or cinnamon.