In a large bowl, combine the flour, baking powder, salt, and sugar. Cut in the butter or margarine until the mixture resembles coarse crumbs.
Gradually add warm water, mixing until a soft dough forms. You may need more or less water, so add it slowly.
Turn the dough out onto a floured surface and knead for about 5 minutes until smooth. Cover with a clean cloth and let it rest for 30 minutes.
After resting, divide the dough into small balls (about the size of a golf ball). Flatten each ball into a disc shape about 1 cm thick.
Heat vegetable oil in a deep pan or skillet over medium heat. You need enough oil to submerge the vetkoek halfway.
Carefully place the dough discs into the hot oil, a few at a time, without overcrowding the pan. Fry for about 2-3 minutes on each side, or until golden brown and cooked through.
Remove the vetkoek from the oil and drain on paper towels to remove excess oil.
Enjoy your meal!