Peel and quarter the potatoes. For medium- large potatoes, cut into smaller chunks.
Place the potatoes in a large saucepan and cover with cold water to about an inch above the top of the potatoes.
Add 3/4-1 tbsp of salt to the water and taste the water. It should be salty like the sea. If not, add more salt.
Place the saucepan on the stove over high heat until the water boils. Turn the heat down to a simmer and set the timer for 15 minutes.
Use a knife or fork to check the doneness of the potatoes. The largest ones should be soft and tender.
Once soft, drain the potatoes in a colander over the sink. Return the potatoes to the saucepan and place back on the stove.
Over low heat, allow the potatoes to dry in the saucepan. Once the sizzling has stopped, they should be ready. Careful not to burn them. Stay close to them during those few minutes.
Remove potatoes from the heat and place in a large mixing bowl. Mash them using a potato masher or potato ricer.
Melt 2 tbsp of butter and pour it over the potatoes. Lightly stir in the butter.
Taste the potatoes for seasoning. If they are salty enough, do NOT add anymore salt. If not, add ¼ tsp, taste and add ¼ tsp more. Continue this until you've reached your desired seasoning.
Add the remaining ingredients: pepper, baking powder, and flour. Stir the mixture together. It will be crumbly.
On a lightly floured surface, spoon out the mixture (or using your hands, bring it together like a dough and scoop it out).
Knead the dough until it is well combined and smooth.
Cut the dough in half. Place one half aside while working with the other.
Flatten one half of the dough into a round about ¼-½-inch thick or 9-10 inches in diameter.
Cut the dough into equal quarters and lightly dust each quarter with flour.
Repeat with the other dough half (flatten it out and cut it into quarters.)
Melt 1 tbsp of butter in a 12-inch skillet over medium heat. Add 4 farls and cook covered for 4 minutes. You may need to lower the heat if the farls are cooking faster than 4 minutes. If the farls are not golden brown on the underside after 4 minutes, raise the heat and continue cooking.
Remove lid and check that the underside is crispy and golden brown. Flip each farl over. Leave uncovered and cook for 4 more minutes. The farls are done when both sides are crispy and golden brown.
Remove them from the skillet and place each on paper towels to drain.
Repeat the process with the other batch of 4. Heat 1 tbsp of butter in the skillet and cook the farls for 4 minutes on each side. Cover the farls with a lid ONLY during the first 4 minutes (uncovered on the flip side will keep the cooked side crispy while the other side cooks)
Eat immediately and enjoy!