Preheat oven to 375 degrees Fahrenheit (190°C).
Line a baking sheet with parchment paper (optional).
In a large bowl, whisk together the flour, baking powder, salt, and sugar.
In a separate bowl, whisk together the oil, egg, and milk.
Pour the wet ingredients into the dry ingredients and mix until just combined.
Turn the dough out onto a lightly floured surface and roll it out to a thickness of about 1/2 inch.
Use a biscuit cutter or drinking glass to cut out circles of dough.
Place the buns on the prepared baking sheet and bake for 10-12 minutes, or until golden brown.
Let the buns cool on the baking sheet for a few minutes before serving.