Boil potatoes in a pot of salted water until you can easily pierce them with a fork, about 10-20 minutes depending on how large your potato chunks are.
Drain water with a colander, then place the colander over the now empty pot and let sit a few minutes over the hot pot to steam dry.
Tip the cooked potatoes back into the pan to mash.
Add butter and mash together with a potato masher (or potato ricer) until no lumps remain.
Transfer the mashed potatoes to a large bowl.
Add the flour, baking powder and salt to the bowl and mix together until fully combined. You should have a thick, soft dough.
Transfer the dough to a lightly floured surface.
Form the dough into an 8 inch round disc.
Cut the dough into 8 equal wedges.
Warm a large non-stick pan or well seasoned cast iron skillet over a medium-high heat.
Brush oil and/or butter.
Once hot, add a potato cake to the pan and let cook without moving for about 4-5 minutes or until golden brown on the bottom.
Flip and cook the other side or until golden.
Transfer to a wire rack to finish cooling and repeat with the remaining dough.
