In a large bowl, combine the flour, yeast, sugar, and salt.
Add the lukewarm milk, melted butter, and egg.
Mix until a soft dough forms, then knead for 8–10 minutes until smooth and elastic.
Place the dough in a lightly greased bowl, cover, and leave to rise for about 1 hour or until doubled in size.
Punch down the dough and roll it out to about 1 cm thick.
Cut the dough into diagonal (diamond-shaped) pieces.
Heat the oil to 170–180°C.
Fry the pieces in batches for 2–3 minutes per side until golden brown.
Verwijder met een schuimspaan en laat uitlekken op keukenpapier.
Mix the sugar and cinnamon together, then roll the warm skuinskoek in the mixture until evenly coated.
Serve warm or at room temperature.