In a large bowl, whisk together the flour, baking powder, salt, and sugar.
Add the chilled, cubed butter to the flour mixture. Use a pastry cutter or your fingers to cut the butter into the flour until the mixture resembles coarse crumbs.
Gradually add the milk to the flour mixture, stirring until a soft dough forms. If the dough is too dry, add a little more milk, one tablespoon at a time.
Turn the dough out onto a floured surface and gently knead it for about 1-2 minutes until it becomes smooth.
Roll the dough out to about 1/2-inch thickness. Cut the dough into rounds using a biscuit cutter or the rim of a glass.
Heat vegetable oil in a skillet over medium heat. Fry the dough rounds in batches until golden brown on both sides, about 2-3 minutes per side.
Remove the Johnny cakes from the skillet and drain on paper towels. Serve warm.
Enjoy your meal!