Follow the steps in order for the best result.
Preheat your oven to 475°F (246°C). Lightly grease a baking sheet.
In a large mixing bowl, whisk together the flour, baking powder, sugar, and salt until thoroughly combined.
In a separate measuring cup, measure the oil and buttermilk. Do not mix them together yet.
Pour the oil and buttermilk mixture all at once over the dry ingredients in the bowl. Mix gently until just moistened. Avoid overmixing; the dough should be slightly sticky.
If the dough appears too wet, gradually add a little more flour until it reaches a workable consistency. The dough does not need to be kneaded.
Using your hands, shape the dough into biscuit rounds and place them onto the prepared baking sheet.
Allow the biscuits to proof (rest) on the baking sheet for 10 minutes.
For a golden-brown finish, prepare an egg wash by whisking together the egg and water. Brush the tops of the biscuits with the egg wash before baking.
If you prefer a sweeter biscuit, especially for desserts like strawberry shortcake, lightly dust the tops of the biscuits with sugar and brush with melted butter (or use the egg wash) before baking.
Bake for 10-12 minutes, or until the biscuits are lightly golden brown. Baking times may vary depending on your oven, so keep a close eye on them.
Remove from the oven and let cool slightly before serving. Enjoy!